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FAQs about Holes, Drilling for Plumbing Marine Systems 3

Related Articles: Plumbing Marine Systems by Bob Fenner, Myth of the One Inch Beast (Why Relying on One Inch Overflows... or Overflow! Is foolhardy) by Scott Vallembois, Plumbing Return Manifolds, Refugiums

Related FAQs: Holes & Drilling 1, Holes & Drilling 2, Holes & Drilling 4,  & FAQs on: Rationale/Use, Designs, Fittings, Sizing/Number/Placement, Tools & Processes Themselves, Related Plumbing, Troubleshooting/Repair... Marine Plumbing 1, Marine Plumbing 2, Marine Plumbing 3, Marine Plumbing 4, Marine Plumbing 5, Marine Plumbing 6, Marine Plumbing 7, Plumbing 8, Plumbing 9, Plumbing 10, Plumbing 11, Plumbing 12, Plumbing 13, Plumbing 14, Plumbing 15 Plumbing 16, Plumbing 17, Make Up Water Systems, Pumps, Aeration, Circulation, Sumps, RefugiumsGear Selection for Circulation, Pump Problems Fish-Only Marine Set-ups, Fish-Only Marine Systems 2, FOWLR/Fish and Invertebrate Systems, Reef Systems, Coldwater Systems, Small Systems, Large SystemsWater Changes Surge Devices

Watch out for plumbing-stoppers.... some livestock gets sucked up all the time...

Stand integrity, Hole cut-outs around and tightening of bulkheads 7/23/05 Hi guys, and thanks for all of the great advice so far. <Hi Randy, Ali here> I am ready to cut the top of my diy tank stand to accommodate the bulkheads from my tank.  I have some questions about how much room I'll need around the bulkheads.  Here is a picture of the bulkhead nuts sitting on top of the stand http://home.cfl.rr.com/homebrewed/fish/180-039.jpg .  The stand top is about 1" of plywood, then there will also be a 3/4" layer of Styrofoam under the tank, so the bulkhead nuts will be stuck way up inside the part I cut out.  Can you picture what I'm talking about? <I think so...> I was planning to start with at least 1" of clearance around the bulkhead nuts. <1 or 2" of clearance would be fine, I doubt cutting the top of the stand to create a 2" of clearance would hurt the integrity of the stand. Additionally, it sounds as if you have a frameless (Lee-Mar style) tank, if this is the case then as long as the tank is fully supported on the corners, then the bulkhead cut-outs won't matter as much, go ahead and start cutting :) >   But do I need to get some type of tool on the nuts to tighten them down?  I don't think I'll be able to hand tighten them very easily since they'll be surrounded by plywood. <No tools necessary, good ol' fashion hand-tightening them would be fine. Even if it's just using the tips of your fingers to tighten them, drink some Gatorade and flex your muscles - YOU CAN DO IT!> Just make sure the I don't want to cut out any more material than required, since I'm concerned about the tank top bowing in the area around the cutout. <As long as the tank is properly braced at the top, bowing shouldn't be a real concern> Thanks!! Randy <No prob, good luck Randy. - Ali>

Plumbing... through-puts... 7/6/05 Hi there Great website.....learned a lot from it....... I really need some advise.......I'm setting up a new marine tank. To be exact 180 Gallons (saltwater).  My question is : what size overflow and return should I have drilled in the tank to have a good turnover of water flow. I'm not planning to have a overflow box but just risers. I was wondering if 1 1/4 inch overflow with a 3/4 return is sufficient. <I would have two each of these minimum... better to go with two 1 1/2" and 1"> I was also thinking of only drilling 2 hole with a 1 1/4 inch bulk head and having a 3/4 inch return running through it...is that a good idea... <... for what reason?> But what s really important to me is what s the best and easiest to have good results ... Thanks for your time and understanding Rick <If you're unsure, keep studying... start here: http://www.wetwebmedia.com/plumbingmarart.htm follow the linked files above, keep good notes... till you know what you want for sure. Bob Fenner> Placement of drilled holes in tank 6/22/05 Hi all, and Thanks Anthony, Have just registered on reefcentral.com and look forward to some browsing, (need more hours in each day!) <There are many great free content websites on the Net. Do consider the anecdotal nature of all though when gathering info and making a consensus.> The two holes for the drain to sump will go near the top with a weir across the back of the tank. Where would  be best to place the return holes bearing in mind I have never gone this route before, have always gone for the up & over job which personally I don't like because it's just messy. <The drilled returns are purely a cosmetic issue. Drill wherever is most convenient/attractive to you... but do know that if they are at or below the active running level of the display... they will back siphon below your overflow weir in the event of a power outage! And to use check valves to prevent this is not foolproof/safe. The best is to release water at to above the water's surface (hence the popularity of perimeter closed loop manifolds).> I am using a Deltec AP 850 skimmer which I am going to put in the sump.....(the input pump to the skimmer that is, not the whole skimmer) Oh, and I will get your book as soon as I can find it Anthony! (If you put one on eBay as a "buy it now" and let me know, I will buy it?) .... let me know?............ Cheers for now. Simon (AKA robinjoye  on eBay) <Thanks for the offer... but I'm really an anti-capitalist. I seem to make (just) enough money to feed myself despite my best efforts. Kindly, Anthony>

Ordering tank today - would like expert opinion on drilling plan ! Hi guys and thank you so much for the information you are providing for all of us around the world!  I'm going to order a tank, probably today, and I'd love to get your opinion on the drilling plan I have laid out.  The main constraints are: 180g tank, holes in bottom only, single end overflow, reef ready flow rates with minimal noise. My plan is to provide for two 1.5" drains and two 1" returns in overflow and then a closed loop of 1.5" intake and two 1" returns.  Here is a PDF of the plan: XXXX, <has address info.> Any input would be appreciated, although I may have ordered it already! Thanks again, Randy <All looks good w/ the exception of the two "middle" 1 3/4" holes. I would not drill these... structurally not a good idea, not needed. Bob Fenner> I just remembered that the PDF I linked to in my previous email contains my name/phone/address - please don't post that on the web site!  Thanks! <Thank you for this. I omitted the link ref.... would like to include just your graphic if you can/will send this along. Bob Fenner>

Re: Ordering tank today - would like expert opinion on drilling plan ! Hi and thank you very much for your reply.  I have revised the pdf to remove the personal information.  I can also send you a JPG if that would be better. <Either one... the jpg would be better> I have some more questions about the 180g drilling plan if you have the time.  I thought I would need at least two 1.5" drains into my sump.  However, I have received some advice that I only want about 1000 gph through the sump and I think a single 1.5" drain should handle that flow, right? <Mmm, better to have two... less noise, less possibility of real trouble should one become occluded, slowed> Then I would need another 2000 gph through a closed loop if I want "decent" flow, but even that would note be quite 20X.  I just can't seem to get enough holes through the bottom of my tank with just a single end overflow.  I also want to avoid having the overflow go completely across the tank, visually I don't really want to see that from the sides. Is it OK to have the closed loop intake drilled through the bottom near the far corner (away from the overflow)? <Yes> I'm not sure if you saw that one or not... <Did> I'm also looking at ways to have the closed loop intake come through the front of the overflow in two places (my overflow is getting crowded...) My goal was the ability to have 3600 gph, but I don't think I can get that with one overflow and one closed loop.  I think it will end up requiring a powerhead in the tank or an additional closed loop somehow...  Where can I put more holes in this thing?  :) <The other corner...> Thanks so much! Randy <There are some fine "in place" pumps... look to Tunze's lines here, if you find you want more circulation. I think you will be fine. Bob Fenner> Placement of drilled holes in tank 6/18/05 Hi crew, <Howdy!> Haven't been in touch for a while (6 months or so) <Nor I... with reality. Hoping to return one day... enjoying the view in the meantime :)> but I wish to ask what may seem a fairly straight forward question but one which I seem to be getting several answers. I will try to explain keeping it as short as I can. <Rock on my salty brother>   a.. Briefly:- Ordered new tank 48"X18"X24" high. Asked for two holes (2"each) to be drilled in back panel  near the top. (To go to sump) <Excellent>   b.. One week later received phone call to say they could not do this and had broken two panes of glass trying. <Strange... I have the same sized aquarium with two 2" holes as well as two 1" holes. They must have had poor skills/equipment. No flaw of the tank/size here>   c.. Company asked me if it were ok if they drilled the holes at the bottom of the back panel instead? <Yikes! What's the difference in glass/panes?> I said that would be fine but suggested they drilled the at the bottom and then turned the glass up the other way so the holes were at the top ;-) <Ha! Spot-on my friend!!!>   d.. (I think they were trying to drill it after construction)   e.. Anyway. Received tank with two holes drilled in rear panel RHS one above the other with a weir ! <OK. Are the holes split? That is to say, one above and one below the weir? If so, make the bottom a closed loop manifold intake>   f.. Messed around and got tank working but found the weir was too high and for the water overflow the weir I had to fill the tank until the water touched the cover glasses.....Not good. <Ughhh.>   g.. Phoned company and complained. They agreed to replace the tank with a new one to my specifications. And that is where I am right now. The tank will be a reef tank and I would like to move my remote 6" deep sand bed to the display tank itself. This will leave one sump for Algae growing to transport nitrate from the tank. The tank size will be 48" X 18" X 30" high. (the extra 6" on the new one to accommodate the DSB). Filtration will be this DSB, plus large protein skimmer, live rock, carbon & ozone. <All good> My question/s is/are this. Where and how would you build the holes for the outlet to the sump? Bearing in mind I am following you guys example and hope to turn the water over between 15-20 times per hour. Would you incorporate a weir? <Yes... I do strongly prefer an internal weir (internal overflow) to improve the quality of (concentrated) protein-rich skimmed water> I hope you can help me out as I do not want to fall into the same traps I have before. <Do check the archives (keyword search from our home page) for "internal overflow" and "marine plumbing". Lots of pages here to consider. Also... I have several link heavy threads with pictures/examples of the closed loop manifold and internal overflows in my "All Things Salty" forum at reefcentral.com. As far as how many/which size holes to use. My advice is actually to have a modest amount of water (say 5-10X turnover) make the loop between the sump and display. This will keep things quiet in the sump and spare turbulence/micro-bubble problems with aspiration through the return pump. Then... use the/another (drilled a few inches lower in the tank) 2" hole for a closed loop pump (this does not enter the sump loop circuit). to provide the rest of the tanks water flow needs in the display proper. Much quieter overall. :)> Keep up the great work and don't please ever give up this site! Best wishes to Bob, Scott, Marina and all of you. Cheers, Simon. <best regards, Anthony :)>

Placement of drilled holes in tank II 6/20/05 Hi Anthony, Really appreciate the reply, very helpful thanks. <You're always welcome bro> The question about the holes? No, they are not split they are one above the other and the weir encompasses them both. <Wow... a very deep overflow indeed if horizontal> But, that doesn't matter now that they are going to replace the tank. I would like to pop another question or two your way, before I give them instructions on building the new tank. It's very helpful to know that the complete 15-20 times per hour turnover does not have to pass through the sump. This does solve a few worries, thanks again for that one. <Very good... and it opens the door for more flow if you go with Acroporids, for example> What I really want to know now is, if I build the tank with two 2" holes for the outlet to the sump in the back panel at the top and two 1" holes for the return,  where and how would be the best way to surface skim the water? <This depends on the style/model of skimmer you choose. Do see the excellent skimmer threads we have in my forums (stickied at the top) at reefcentral.com (skimmer performance) and reeffrontiers.com ("skimmer 101" thread)> where would the weir go exactly? <If horizontal... as low and long as possible. About 6"/15cm deep and about as wide or a little bit thinner. And running the length of the tank as much as possible. This will thin the surface extracted water and greatly improve skimmer production. Do a search for "internal horizontal overflow" on this site and the others listed above for more info on this. Or peek in my first chapter of the Book of Coral Propagation for an illustration and detailed description> Would it be best to have an end to end weir at the top of the tank? <Yes> Also how far down from the top of the tank will be best to have the TOP of the 2" holes and the 1" ones come to think of it? <As close to the top of the tank as is sound/possible. The depth of the overflow that holds these two holes will likely be no more than 6"/15 cm at the top of the tank> Sorry to fire so many questions at you but you guys have certainly saves me from a  disaster or two in the past. (That reminds me, I owe a cold beer to all of you!) <Looking forward to it :)> Oh, one last thing. If I use powerheads (Tunze streams, thanks to Anthony and/or Scott, I would use nothing else now, they are brilliant!!) do I count these in the equation regarding total water turnover? <Yes... certainly> Cheers again. Simon. <Best regards, Anthony>

Turnover... drilled tank fitting size, pumps Hi Crew: <Greg> Anthony and Bob have been immensely helpful in the past (as have all the FAQs even if I don't have that particular problem/issue. Just fun to read!!). I have a quickie for you. I hope. I am moving soon and want to set my tank up with the sump and refugia in the basement.  Necessary info (I hope): 110 Oceanic (5' long, not the "high" version) w/ 2 - 1" overflows <Mmm, wish these openings/through-puts were larger in diameter, perhaps more numerous> 55g sump <Nice!> 2x 30g refugia <Wow, even nicer!> Do you guys have a recommendation for a pump that will accommodate this system at 15x - 20x turnover at 12-14' of total head? <Mmm, unfortunately, not through those one inch diameter fittings... Please hear me out here... You might be able to "get by" using both of these for drain/lines... pumping the water back "over the top"... and having some of the flow go through your refugiums enroute to the 55 sump... But, if it were at all possible, I would have this tank re-drilled... leaving the two current openings for returns, and adding two-two inch (or even two and a half inch) inside diameter holes for bulkheads to be used for conducting water down below...> Or should I just plan to have several powerheads? <Mmm, if necessary... but I am not a fan of such in large systems> I would prefer not to have too many powerheads as I have my tank stable at about 80 degrees F with my halides and the setup I have.  Would a pool pump be a good option or just too noisy? <Likely so... and too likely a candidate for rust troubles... Do look into the many fine lines of pumps... these are gone over on WWM> Thanks for all your help. past. present .future!!   Greg <You were, are and will be welcome. Bob Fenner> Standpipe noise, tempered glass tanks Hi Guys! Me again. <Me too!> I have read several articles about this topic, but none that help me... <Keep reading> so here goes: I have a 65 gal FOWLR set up. I just had the back drilled, and I plumbed it on down to the sump... Flowin' like a champ. However, despite how much water I send down the shoot, I get that sink-draining sucking sound. Here is what it looks like... Bulkhead is about 5" from water surface, 90 degree PVC, that goes to a 1"(or so) threaded adapter, with one of those cone shaped skimmer thingymabobs on it to keep the little guys from getting sucked in. Out the back, there is another 90 degree, that is facing 45 degrees downward, and that is attached to some reinforced 1 1/4 ID tubing... That flows on downward to the sump. Once it gets in the sump, there is a MAG-7 pushing water back up.  I cut out a few of the "bars" on the thingymabob, thinking it was too restrictive, and it did increase the flow, but did nothing for the flushing sound. Is there some sort of a baffle, or trick that would fit this set up and make my living room a quieter place? Everything I read, is for bottom plumbed systems.  <A few tricks... I'd try installing an aspirator here...> ALSO.. for your readers who might be thinking about drilling an aquarium... IF you have an ALL GLASS or an ODELL 55gal, and you wanna drill it... and you bought it at a chain store (Wal-Mart, Petco and so on). DON'T ! Despite the sticker saying "tempered bottom"... The whole %#%&& thing is tempered ! Let me tell ya... it is LOUD when it blows...and takes the diamond bit with it. <Yeeikes!> IF you bought the tank from a private dealer... ONLY the bottom is Tempered, and drill away. This is fact, and was verified by All Glass... Thanks again in advance guys !!  John Mulrooney  <Start reading here: http://www.wetwebmedia.com/dursopipefaqs.htm and on to the linked files above. Bob Fenner> 

Plumbing Question I am planning a new 125 gallon tank and have a plumbing question that I cannot find the answer to in you comprehensive archive.  I want to achieve 20 times flow, so have special ordered a tank with two overflows with 1.5 inch drains and 1 inch returns.  I would like to use the Dolphin Ampmaster 3000 that has 1.5 inch fittings in and out.  Instead of running all of the flow through the sump, I was planning to have one drain go into the sump and the other connected by a tee fitting right at the pump intake, essentially making that overflow a closed loop.  After leaving the pump, I would tee off the 1.5 inch line and reduce the pipe size to 1 inch before returning to the tank.  Will this work or will I need a valve on the "closed" portion to ensure all of the lower head pressure sump water is returned at the same rate it drains? <Mmm, let's see... you're planning on using the one pump to draw water from both the sump (that is gravity fed I take it) and one of the 1 1/2" overflow fittings? If I understand you here I would not do this... for a few "reasons"... principally the likelihood of a power outage, pump failure... that would drain the water down through the pump and overflow lines... and depending on the size of the transit volume sump, position of the through-puts, over on to your floor... I encourage you to draw all this out, including plumbing, fittings, valves (I would have these before and after the pump/s) to facilitate their manipulation/removal... and a large sump, possibly another as a refugium (low flow)... Whatever pump you end up with I would NOT reduce the discharge of the line size from the volute. In all likelihood you are looking at using two pumps... perhaps one can be used for the sump/s and protein skimmer... Bob Fenner>

Pump(s) for a Oceanic 200-gallon RR FOWLR Aquarium, actually overflows, pump/plumbing considerations Hello, <Hi there>             Hope things are going well for you guys and gals. Please give me your recommendations for a pump to return water from my sump to a FOWLR aquarium. The Oceanic Rep. States the aquarium has a flow rate of 1400/2000 gph. The 2-return lines to the aquarium will be 3/4" PVC pipe and the drain lines will be 1" PVC with Durso Standpipes. <Uhh... two 3/4" inside diameter lines? I think the estimate of how much flow you can realistically expect from these fittings is dangerously over-expectant... Hear me out please... I would NOT design, install or maintain a system that did not have at least fifty percent redundancy in provided capacity here... that is, for example, if one drain line would do, I'd have two of the same size... You do NOT here... depending on how you rig your plumbing, what sort of screening you have over these two drain lines, you can be in GIANT trouble in short order... should one become occluded. DO consider your options... if it were me, my system, I would have it (re)drilled for at least two 1 1/2" inside diameter overflows (2" holes)...> Presently my options are to use 2-Iwaki MD30RLXT pumps (960 gph @4') with the outlet reduced from 1" to ¾" or to use 2-Supreme Mag-Drive 12 pumps (950 gph @ 6'). <Stop! Do NOT reduce the discharge diameters... and please show this correspondence to whoever has been encouraging you to do so... what you are suggesting is akin to buying an automobile with excess horsepower and driving with the parking brake on... don't reduce the diameter of the plumbing from your volute/s. Again, if necessary, have the available hole/s re-drilled> The overflows are located on the corners of the aquarium. I am looking for pumps that are quiet, efficient, and dependable (who isn't, right). Should I use higher flow pumps and throttle-down the flow with gate valves or will that hurt the pumps. <Might... will increase waste heat production, your electric bills> I was also told I could add two more return lines to run along the back of the aquarium and use a larger pump. If you know of a better option, please suggest. The system will also have a refugium and Euro-reef Skimmer. This is the correct flow path, water to protein skimmer, to refugium, to pump, to aquarium or water to sump to protein skimmer, to refugium, to pump, to aquarium? Using a refugium will be new to me. <Mmm, a bunch to say. First, please read through our archived FAQs on Pump Selection: http://www.wetwebmedia.com/pumpselmar.htm and the linked files (above, in blue)... then the MANY FAQs on Sumps, Refugiums... you can find them indexed here: http://www.wetwebmedia.com/marine/setup/index.htm You DON'T want to run this much, all the water through a refugium... maybe you can fit another sump for transit volume... Bob Fenner> Thanks, GDG

Re: Pump(s) and through-puts for a Oceanic 200-gallon RR FOWLR Aquarium Hello Bob, Thanks for the reply and I told the LFS to call Oceanic and hold my aquarium because I need the holes drilled larger. <Ah, very good> I have been reviewing the posts on the website and I thought I had it correct for the aquarium set-up. The flow set-up I was going to use was the one included in your "Plumbing Marine Aquariums" article on the site that has a picture of the refugium. I will have Oceanic install three overflow boxes in the aquarium, on both ends and one in the middle. The drain holes will be 2" drilled and the return holes drilled 1 3/4", thus having 3-1 1/2" PVC drains and 3-1" returns. I will redo my plans for the Euro-Reef skimmer CS (12-1), sump size is not determined as of yet, and 58-gallon refugium. Your comments are greatly appreciated. Could you recommend so books that could be of help with FOWLR, I have your book already? Thanks again. GDG    <Anthony Calfo's "Book of Coral Propagation" and our "Natural Marine Aquariums, Reef Invertebrates" books, though sounding like they are strictly "reef" would be of good use to you... mainly to further firm up what you already know intuitively, and will want to know soon. Sorry if this "plug" seems overly self-serving, but these indeed are your next best sources of input. They may be available at a local library. Bob Fenner>

Tank plumbing Greetings Crew! I am in the process of upgrading my 40 gal tank to a 75 gal (w00t, yes...) and have a couple of (nagging?) questions. I have read, read, and re-read countless articles you have on the WWM archives re drilling the new 75gal acrylic tank.  I have drilled the overflow (2" through put) (center overflow) <I'd make at least one more.> but am still undecided (hesitant?) to drill the returns.  The tank itself does not lend to the non-drilling (pump -> t-bar -> over tank output) type of return, so it must be drilled.  Currently I'm thinking of having my Iwaki WMD30RLXT (1" output) branch off to 3/4" t-bar to 4 returns (4 return holes in tank).  I know that 2 of them will be on the outside, and high up (re power outage/siphoning), but the other 2... I *was* thinking of placing them on the same plane and just have them pointed more downwards in the tank for circulation purposes.  Should I maybe consider another approach, what would you do if this were your tank? Thanks as always, Craig <Your approach is a good one... if you wanted to, you could drill just the two holes for two discharges each, tying two each together inside the tank... Bob Fenner>

- Tank Modifications - Holy moley what a site!! You guy's really put a lot of effort into this stuff and I sure appreciate it. I have a 58 gal Oceanic tank that I am going to drill to mirror Mr. Calfo's design. If you could spare a couple of moments, I would like to get some clarification on a few specifics: 1) For the internal overflow, can I use acrylic or should it be made of glass? <Acrylic would be fine.> If acrylic, can I use Weld-on for adhesion to glass? <No... Weld-on will not bond the acrylic to the glass. You must you silicone adhesive... 100% pure, made for aquariums.> 2) Should "teeth" be routed into the acrylic/glass? <It would be best.> If so what do you believe is optimum spacing and depth? <I'd say at least one inch in depth... spacing is really up to you. What "optimum" is varies to much to say.> 3) I am planning on drilling 3, 1" ID (1.75 OD) holes for 1" bulkheads. Does the internal overflow have to span the entire length of the aquarium or is this merely suggested? <That would likely be excessive... probably better to use the shelf design proposed by Mr. Calfo.> If it is best to span the entire back of the tank, where do the returns come in if I wish to use Sea Swirls? <With Sea Swirls, you have no choice - they have to be positioned somewhere along the top of the tank... seems like you need to make some decisions - some part of your plan needs a drastic change.> 4) As for the bulkheads, I plan to cut them 2" down (center of hole) from the top frame and evenly spaced from the sides (not to come close to 2" from either side). Does this sound ok or is 4" to center better? <Sounds ok either way.> Like all others before me, I appreciate the time you spend to answer these questions. Mark <Cheers, J -- >

- Tank Modifications, Follow-up - Thanks for the prompt response. <My pleasure.> Just one point of clarification. <Sure.> I meant to say that I would be using the shelf design as outlined in the book. My concern was is it possible to drill the holes needed centered on the back wall, 2" down from the top and sufficient distance from one another, and have this shelf built to span only what was needed to cover those drains (I.E. 12" - 16" of shelf covering the drains along the back wall)? <Should work fine, yes.> Then I would have space at either side of the shelf for returns, be it Sea Swirls or whatever. What do you think? <Yup, makes sense and will allow for the Sea Swirls.> Lastly, how far down from the bottom of the bulkheads can I end the shelf? <Likely right below the bottom of the flange.> In other words, if my drains are cut at 2" - 4" at center and the bulkhead bottoms are at 3" - 5", can I end the shelf just below the bulks? <I think so, sure.> Will this hamper water volume/flow in any way? <It may, but the beauty of silicone is that you can remove, re-glue if necessary. You are going to do a full set of leak tests before you fill with saltwater, yes?> Thanks so much for al of your help!! <Again, my pleasure.> P.S. Do you know any tank drillers in Northern NJ? <I don't - you should check on some of the forums, I'm sure you'll find someone in your area capable of doing this.> Thanks again!! <Cheers, J -- >

Overflows If it were your tank: How many & what size holes would you have drilled on the back wall of the tank (assuming a pump that can handle 3600gph at 6-8ft of head)? <For a 180 gallon, likely six foot tank? Three, one toward each corner and one in the middle... of 1 1/2" inside diameter> I have heard that the reason people do the in-tank overflow is that the water builds up after going over the overflow creating more of a vertical push into the outflow tubes vs. a couple top of the back tank holes which outflow horizontally.  Does that make a substantial difference for flow? <Mmm, am concerned I may not be understanding you here, but the only real difference in such arrangements is the addition of horizontal piping, fittings, rather than more initial vertical drop> If I understand you correctly, it sounds like your advice would be to drill 2-3 holes on the upper back tank walls, use bulkheads & screw in strainers, and then on the outside of the back tank wall, simply connect hard or soft plumbing leading to the sump? <Yes> What distance is advisable for the holes to be drilled from the top of the tank? <Two or four inches in this case/size bulkheads... to either attach screening horizontally or (with the four inch gap) attach threaded elbows... Bob Fenner>

Building  a large glass tank I am planning to build a 180 gallon glass aquarium. <Hey Mike, MacL here with you today.> I am new to the hobby and have tried to read as much as I can on water circulation/overflows. <Very smart.> I plan to do FOWLR, but would like to plan for the eventuality of going reef.  There is a lot of articles discouraging the use of hang on overflows. <I think that's because many of the overflows have problems.> I have read a little on Durso overflows, horizontal overflows, some of the DIY overflow designs.  It has all become a little confusing. <I can see where that would be.> In your experience/opinion, what are the best options for high flow, and as silent as possible overflows. <Personally I would drill the tank for optimum overflow and I'll be honest and tell you that my first tank originally was set up with a corner overflow and I will NEVER do that again.  I have ended up with a lot of detritus that I cannot get to clean it up in the overflow and I hate it. My newest tank will have the holes drilled into the main part of the tank and on the back. Let me know what you decide and if you have any more questions. MacL>

- Overflow and Water Level - been searching at the FAQs but to no avail.. a quick question here.. how do I set my desired water level at my display tank? I have two choices re-over flow; 1.) a hole drilled at the lower back side that can hold 2" PVC ending a stand pipe; how tall should be the standing pipe in order to achieve at least 3" water line below the top edge? 2.) a 2" bulkhead drilled at the back; how far from the top edge it should be drilled to get water line same as no.1? waiting for your help, again.. thanks! -Arnold <Hello Arnold.  When you install the stand pipe I would keep it a length about 1/2inch lower than where you want you actual water line. A lot is going to depend on the flow rate of the pump.  If the pump gph exceeds the ability of the standpipe to remove water then you will need to put flow control on the return. James (Salty Dog)>

Re: overflow my tank measured 22" in height but I'm keeping my water line down to 19" all the time (it's a freshwater tank and converting to salt) and I want to run it same way for the SW. and assuming that height would be fair enough for fluo lighting.. thanks J, happy new year! >>>Arnold (",) <Hello, by fair, did you mean "far enough away".  If you use a glass top it really doesn't matter where your water line is, and you should use a glass top to prevent premature rusting etc of the light fixture. James>

- Overflow and Water Level - Been searching at the FAQs but to no avail.. a quick question here.. how do I set my desired water level at my display tank? I have two choices re-over flow; 1.) a hole drilled at the lower back side that can hold 2" PVC ending a stand pipe; how tall should be the standing pipe in order to achieve at least 3" water line below the top edge? <How tall is the tank? With a setup of this type, the water level will be just a quarter inch or so above the top of the standpipe. So... you can trim the standpipe to adjust the water level.> 2.) a 2" bulkhead drilled at the back; how far from the top edge it should be drilled to get water line same as no.1? <Again, where you put the bulkhead will determine the water level... in this case you can bet that the water entering the bulkhead will be at least half its diameter, perhaps a little more.> waiting for your help, again.. thanks! -Arnold <Cheers, J -- >

Bulkhead and flow rate...vs. gravity fed flow rate? Hello, Quick plumbing question here. I currently am running a successful reef 90g. I want to add a small ...40 gallons prop tank beside it. <Neat, sounds good> I intended on feeding it through a section of U-shaped pvc at 1/2" in diameter, <Mmm, stop! Do make that larger diameter, at least one inch, and double them (use two), lest one fail due to... many possibilities!> and have a small return pump in the prop tank to return water back to display. Can anybody help me to figure out the GPH of a 1/2" GRAVITY FED U tube....siphon started. As well would this be the same gph if a 1/2 bulkhead were placed here at the side wall of the aquarium? thanks in advance. <Mmm, there are formulae for calculating probable water level differences (what I suspect you're really after), but I would not be concerned with these... Other issues (like screening, figuring how to prime lines (with slip caps no doubt), and taking care to make the "U tubes" deep enough (for water changes, evaporation...)... are more important. Bob Fenner>

Re: bulkhead and flow rate...vs. gravity fed flow rate? ok, I think I am confused....If I started a siphon by just sucking on a 1/2 inch tube....the flow would probably be fast correct. In that a small pump, like a maxi jet at 200-300 gph might not be able to handle the return quickly enough....whereas if I used a bulkhead, it would be a slower rate....though if I put a t on the outside for air induction, wouldn't that too speed it up? For example I have an outside overflow box with a one inch drain that handles a mag 18 with a final rate of about 950-1000 gph due to head pressure. So I was thinking to get or make a u-tube,....hang it on the side of tank....suck on it into my 40 or 50 gallon PROP tank....and put a small pimp in there to return right back to display. <Uhh... do not, DON'T try what I think you're proposing unless these tanks are at about the same level. Please read here: http://www.wetwebmedia.com/plumbingmarart.htm and on to the MANY marine plumbing Related FAQs (linked, in blue, at top). Bob Fenner> again , be so kind as to provide me with your educated thoughts. I am rather well versed,....but kind of stumped here-----

Plumbing an overflow for a 72 gal Hi I recently replumbed my 72 gallon bow front tank. I used 3/4" pvc down the middle in the back to about 4" off the bottom and then ran a T to run to both sides along the back with about 3/16" holes drilled along it all around about 15 to 20 holes on each side. Is this in a good place or should it be up higher in the tank.? << Well I'm not sure I follow the design.  If you have holes drilled up high in your tank, then why have a pipe run down into the tank?  The main idea is to take the surface water right off the top of the tank and overflow it into the sump. >> I am running a Little Giant pump at a about 450 g/ph. Do think the pump is enough? << No, I would at least double that flow. But hey, that is just me.  Give it a look and see if you think it is enough. >> Thanks <<  Blundell  >> Rodney Reible

Overflow holes on glass tank plus closed loop Hi crew! <Peter> Great website! I love that you guys cover everything from the most basic to advanced stuff! But of course, I'm writing with more than just compliments :-)   I had a few ideas I'd appreciate any input on. I'm having a 115 tall glass tank made (48" x 18"deep X 30" tall). <Bet you'll soon wish this was eighteen inches tall, 30 deep> Since it's being custom made (Starphire front panel) I'd like to take advantage and have the back drilled (like in Anthony's Coral Prop book) instead of an unsightly clear internal overflow box. Before getting into the hole size/type questions, I guess I need to ask about flow rate. I love the idea of a closed loop/external pump system (have one currently on my 20gal). If I get virtually all my flow in the tank from a closed loop system (up to 30X tank volume), how much flow do I actually need to have going through my overflow/sump? <What do you want to do with this flow? 2-3 volumes per hour will do for a refugium for instance> Is it dependent on protein skimmer pump/size (i.e. volume processed by skimmer vs. volume flowing through sump)? <Yes... if that's what you want to service... let's say rather than a hang-on> Or just enough so the heater in the sump gets enough flow? Any thoughts? <Lots. For heating you don't need much flow either... water is the standard for specific heat... retains thermal energy better than any other substance known> So then, if all I need is minimal flow going through the overflow holes in the back, would 4 - 1" bulkheads be sufficient on this size tank (haven't bought the return pump yet for this reason)? <Fewer, larger would be better... like two 1 1/2" toward the upper, back corners...> I noticed in searching through previous questions that 4 - 1" bulkheads (holes drilled 4 inches from the top of the tank to the middle of the hole) were mentioned as sufficient for a 120G tank. What GPH would I want to be going through these, assuming I want them skimming mostly surface water, and to keep them from being too loud? <More to be considered, specified... like where, how does the water transit from there? How much higher will the water be over the edge/lip of these through-puts? Will there be any plumbing running horizontal from them? Practically speaking the two 1 1/2" fittings will allow much more than the 4 one inchers... a good six hundred gph... if you want more, think you might later... have them drilled for 2" inside diameter bulkheads> Also, how necessary is it to have a shelf/baffle running across the entire back top of the tank to skim the water? <No> I'm thinking 4 - 1" bulkheads with minimal flow will be sucking mostly surface water anyways, right? <You don't want this to happen... too much noise, too great a likelihood of something getting trapped there, too hard to rig intake screens> Thanks for any input! Peter <Read over the archived "Plumbing FAQs" (there are many) on www.WetWebMedia.com until you are centered on your options here. Bob Fenner>

Re: Overflow holes on glass tank plus closed loop Hello Mr. Fenner, <Peter> Thank you for the reply. Only after reading your response do I see how vague my questions were. So let me be more specific. Yes, I would rather have a deep tank instead of tall, but apartment constraints dictate size. So I figure rather than have large sump or refugium volumes, I'd put my extra volume on top, so to speak, therefore treating this tank like a 60 gallon with lots of swimming room on top :-) <I see. I hope you have long arms!> As for the plumbing...the plan is to have the tank drain surface water to a sump, where there will be a protein skimmer, heater, and media like carbon. Dedicated pump will then return water to tank. Refugium will be separate, with a small dedicated pump from the sump; exiting water flowing back to the sump. <Good arrangement> If all circulation in the display is provided by a closed loop, then I can get away with how many gallons running through the sump? <Depends on the size of the sump, fittings, plumbing... there are "average" minima (3,4X), and maxima (10,20X)...> Let's say 600GPH is sufficient. Then, the drains from the main tank could be 2 - 1.5" ID holes in the upper back corners of the tank (how far from top/edge is safe for drilling/final water level)? <Again, depends on the sump somewhat... Imagine a power outage, or outright failure... the water above the lip of the through-puts is going to drain down into the sump... need to test, mark the highest level the sump should be filled to prevent flooding... That being stated having the edge of the cut out down two inches and over four or so is about right> I currently have a small tank plumbed like Anthony described in his book, with a simple horizontal line coming off the back of the near top of tank drain hole, then down to the sump. This is SO LOUD as air gets sucked in just under the upper lip of the bulkhead inside the tank. Is this because there is too much flow running through a 3/4" hole? <Only to a secondary extent> Or because I should have put a T on the bulkhead on the back of the tank, with one part pointing up for air intake, and the other pointing straight down for the water? <This would help... but what you really need is a larger diameter fitting/plumbing, all situated further down in the tank, a "Tee"/Durso fitting, AND a mechanism for silencing the water dropping (an aspiration tube)> I think that if the hole was larger, the water would simply flow down, half filling the drain line, and not making the vortex of air effect it does now. Is this correct? <Yes, possibly> This is why 2 -1.5" ID holes would be OK for apprx. 600GPH? And a T on each drain coming off the back of the tank would not be necessary then? <I would use this, yes> These 2 drain holes would then determine the display water level, would they not? <Mmm, only to an extent... the pumping mechanism is at least as important> I did not understand why you asked in your reply how much above the holes the water level would be. How could they be higher than the drain holes, unless the flow was too great (eek, overflow!), or the exiting drain lines curved up first? <Bingo on both counts> Thank you for any help you can afford me. A realize I could try things, and learn with trial and error (i.e. my super loud 20 gallon, doh!), but I'd prefer not to mess around with this new tank, especially glass. And I'd really like to avoid a large internal overflow box in an already "thin" aquarium. Sincerely, Peter <Have you read over the materials stored on WWM re marine plumbing? You should. Bob Fenner>

Hole, bulkhead size Hi I just got a 2inch hole drilled in my 135 gallon tank. what size of bulkhead would fit in here. I have a 1 1/2 inch but it doesn't fit. The base on that bulkhead in 2 1/2inches. Can you get a 1 1/2 inch bulkheads with a 2 inch base? hope this makes sense Tristan <Yes to the last statement. Look around... there are "thinner" outside diameter bulkheads (the ones for spas/Jacuzzis for instance) that have 1 1/2" inside diameter and less than 2" outside diameter. Spears makes these... and a few places (try MarineDepot.com) offer them for sale online. Bob Fenner>

Reef Aquarium Plumbing 11/9/04 Hi, I've been thinking about setting up my first reef aquarium and when I came to the plumbing I got a bit stuck.  I've been gathering info from other people's comments from your site. <ah, good... I'm hoping you also saw the page on reef plumbing that Bob just penned last week> I'm going to explain my aquarium's specs : Capacity  : 100 gallons I drilled five holes to accommodate 50mm bulkheads each across the width of the aquarium.  I'm planning to put a glass shelf in front of the holes to skim to water surface better. <excellent> I bought an Aqua Medic pump with a capacity 1700 gallons/hr.   Now I would like to confirm for circulation purposes, whether one pump would be enough and I am also going to use the closed loop system.  Do you think the performance of the pump will decrease? <they always do over time as they age and clog> I intend to put coral and live rock and a few fish when I'm finally done with my setup. <17X turnover is good... but if you pick SPS corals and some other demanding varieties, you may need even more flow.> Also, regarding lighting, I've read that 2 x 175W metal halide should be enough.  Do you agree as the height of the aquarium that is the glass is 27 inches? <yes... agreed... these lights are very fine my friend> Thanks a lot for your help, Best Regards Charles Galea Malta <very welcome my friend, Anthony Calfo> Bulkhead sizes Good morning WWM Crew. <Good morrow to you Troy> I am in the process of planning the filtration/circulation for a 120 gallon salt water tank and would like you opinions on bulkhead/pipe sizes. <Okay> The tank, as of now, is going to be FOWLR. What I was thinking was a 1" line going to a 29 gallon refugium, a 1" line going to a 16 gallon sump, and a 2" line feeding a closed loop manifold. Could you please advise on this or what you think would be more appropriate along with pump sizes to push all this. <Mmm, a few things... the drain lines need to be larger... at least 1 1/2" inside diameter... I'd make them 2"... and the discharge/manifold plumbing should be the diameter of the outgoing side of your pump volute, not larger> Thank you very much for your time and knowledge. Troy <You'd likely benefit from reading the marine plumbing article and FAQs posted on WWM. Start here: http://www.wetwebmedia.com/plumbingmarart.htm and on to the linked files (in blue, at top). Bob Fenner>

Drilled hole size and what to do with them. Mr. Fenner,                   First let me say how much I have enjoyed this site. I have learned a great deal but do get confused at times. <I as well> I am in the process of starting up a 150 Gal fish only tank, it has been 8 years since it was last running.                  I read the entire plumbing section and got my tank drilled. I think it may be a bit too much though. I had 4 holes drilled that are 2 3/4 inch for the drains and one 1 3/4 hole for a loop return like you have described. The drains will empty into the basement 10 feet below. The sump is 55 gallon wet dry acrylic. <Some through-puts now!>                 My questions are this........ Should I "cap" 2 of the bulkheads and just use two to return to the sump? <I would, yes... unless you intend to have humongous flow through all four> Should I use all 4 and connect two and two into a "Y" connection, or should I run all 4 to the sump? <Could connect two of two together... but the cost of bulk-heads... I would likely run just two of the four together, and cap the other two> BTW my wet dry has only two one inch holes drilled in the top. I will need to enlarge the holes to fit either 2 or 4 drain lines. <Yes... or retro a drip tray, baffle of some sort to accommodate the flow from above>                 I am shooting for between 750-2000 GPH for flow rate. Did I overkill with the drains {4---- 2" pvc}? <Mmm, yes, but better than under-killing it> Hope this isn't too confusing. I am planning on plumbing to system next week and hope I didn't mess it up.                Sincerely,                                 Jeff Resch <No real problem to cut acrylic or glass and silicone over the other fittings. Bob Fenner> - Bulkheads and Pumps - Good morning WWM Crew. I am in the process of planning the filtration/circulation for a 120 gallon salt water tank and would like you opinions on bulkhead/pipe sizes. The tank, as of now, is going to be FOWLR. What I was thinking was a 1" line going to a 29 gallon refugium, a 1" line going to a 16 gallon sump, and a 2" line feeding a closed loop manifold. Could you please advise on this or what you think would be more appropriate along with pump sizes to push all this. <As far as bulkhead sizes go, it all sounds do-able although two inches may be a bit excessive for a closed loop... at the very least make sure you have screens on the input and output sides so no one swims into it when the power is off. As for pumps... you're on your own there. There are many good brands and several sizes of each. Flow rates should be as high as is reasonable... if you could accomplish 10 to 20 times turnover for the system, you'd be doing well. Much more than that and you may be sloshing water out of the tank. However, I suggest you rethink the plumbing of the two one inch lines going to separate boxes... your overflow rate will be constant to both - if you put different sized pumps on each box, the one with the lower flow rate will eventually overflow. Much better, if you want a refugium to fill it directly from your main sump and let it gravity feed back into the main tank or sump.> Thank you very much for your time and knowledge. Troy <Cheers, J -- > AGA Dual Overflow Hi,   I am new to Lg. Saltwater setups so sorry if this sounds dumb. I ordered from a local store a 125 AGA with dual overflows that are rated at a max flow through of 600 gph per overflow. The store is telling me that I need a pump rated at 2400 gph for each overflow, is this correct? It sounds like over kill? That would mean if I used one pump it would have to be 4800 gph... wouldn't the tank fill faster than it could empty? <Mmm, yes... even discounting for less than rated "performance", head, induced drag in the plumbing lines... I would NOT get/use a pump with more than 1,500 gph rating> Sorry for a stupid question! Kerrie <Doesn't seem stupid to me... Bob Fenner, who has mopped, vacuumed up many, MANY gallons of water from floors>

Drilling for overflow Hello crew!  I have just purchased a 40 gallon glass tank and I want to drill a hole on the bottom for an overflow drain. I believe the glass is 1/4" of a inch thick (non-tempered). my question is, do you think the glass can withstand the weight of the water, substrate and rock without breaking? or should I go with a hang on the back CPR rated for 600gph or 800gph? thanks for any input. <Yes to the drilling possibility. The hole should/will be round (of course) and you will likely have it placed a few inches from a corner. Of a certainty, using a hang-on filtration unit will work as well. Bob Fenner> Bulkhead Frustrations... Good morning crew. <Hi there! Scott F. here with you!> Thank you again Scott for your invaluable advice and by boy, do I need more now!! <I'm ready!> To re-cap. I am/was moving my 6x2x2 mainly fish and live rock display, evolving this to a fully blown reef tank and doing away with most things mechanical. Two sump/refugiums with Caulerpa racemosa in one and DSB in the other. <Ok- I'm up to speed here...> Well, today (make that 3 weeks ago. I wrote most of this then and today is an update. If you see what I mean?) was the moving day!  Only had to move the tank eight feet! Anyway, after moving it across the room I started to fill the tank with fresh water for a practice run. And?......Drip, Drip, Drip, from the tank connectors on both sides of my bottom drilled tank. Each side is fitted with down pipes to help surface skimming. I don't like this setup but due to finances (or lack of them) I am stuck with it for the time being. <"Drip" is not a word that I like to hear...> The tank connectors have soft rubber seals on the top (the water side) of the glass and hard white plastic seals on the underneath side. (They are made by Aqua-Medic and to make matters worse they are metric, all my other pipe work is imperial) Is there anyway you know, that I can prevent these from leaking? Can I put a soft rubber seal on the top and the bottom? or is this not good practice? Should I use silicon? <I'm thinking that you'd want to use something like plumber's putty (on the outside, of course). You may need to experiment here (gulp...). I highly recommend that you consult a hardware store or a good "do it yourselfer" who has encountered this problem before. When you're talking about the potential for serious water damage, you cannot afford to take chances!> <<RMF would try first tightening (gingerly) the nuts to these fittings... with large Channel-lock pliers, a strap wrench... not much... with water in the tank... just cinch them up a skoshe>> Should I do them up from underneath or the top of the tank? I know these are supposed to be hand tight couplings but have now tried hand tight and also hand tight with a quarter turn with a tool, as you cannot grab hold of much of the top nut. Maybe a quarter of an inch it makes life difficult. (I have read of Bob's horror story of the helper who took a tool to a hand tightened seal) I have taken these apart twice now and cleaned them but somehow they both just continue to leak.) Just to make matters worse, I have around twelve not too small fish and all the live rock and corals plus BTA all in a 40gallon tank with just a small trickle filter (I am keeping feeds to a minimum) but the Majestic Angel is scratching! Even worse is I kept the seawater, in airtight containers, thinking this would all be done in a day or less, and is now getting on for three weeks! Should I still use this old seawater? <I don't see too much problem with the use of "older" water, as long as it's been aerated and kept free of external contamination> Perlease ! I need some advice on how to seal this tank connector. The underside of the connectors are also hard to reach, as the tank itself is on poly tiles, then a half inch thick mdf, then more poly tiles, then a pinewood board, so to get at the tank connector under the tank is still very difficult. Can't get a spanner on the two inch nut if I wanted to!  I cannot take the tank off the stand as all the rigid pipe work is glued (solvent) in place and is very rigid indeed. <Grr...> I have now been trying for over three weeks to seal these without success. Have you guys any ideas on what I should do next?  Hope some-one can offer some ideas as I am at a loss now as to what to do with this tank. Many, many thanks you guys. Simon. <Gosh, Simon- I'm sorry that I don't have any really great solution to this predicament...It's kind of tough to develop a plan of action without seeing these guys in person...My best advice is to enlist the hope of a qualified aquarium service technician in your area....Money really well spent, IMO! Good luck! Regards, Scott F.>

Max drain in a 1.75" bulkhead? Hello to the WWM crew! << Blundell here. >> Although I am sure this info is somewhere in your archives I had no luck locating it so here we go.      My 80 AGA RR has a single bulkhead in the bottom of the overflow box.  The inside of this bulkhead is 1.75" wide and the outside is 2.4" wide. << That is big. >> I need to know the max GPH I can run through this so I don't purchase too large of a pump.  I am currently looking at the sequence Reeflo dart which would run about 2700 gph @ 4 foot head. << I bet it can handle that.  I'd try it out, that is really the only way to know. >> What is the max gph I can swing with this bulkhead?  Should I consider a second closed loop pump on a separate manifold (I currently am running a mak4 (1180 gph) on a squid and my SPS need more flow!). << Extra closed loop systems are great.  Really no reason not to have one.  But I think your drain will keep up. >> Much thanks in advance for all your help!  ~CK~   <<  Blundell  >> <... what if there is some slowing down, occlusion here? I do wish there were more than one drain line... RMF> A question re: tank over flow Hi Bob! Arnold here, just a question re: over flow. I cant find any of them at the FAQS. Is there any thing to consider when it comes to making a tank over flow? sort of; size of the hole (bulk head), line down to the sump etc.. But I'm afraid that this local glass shop can bore 3/4" only:(  if I go 3/4",how many holes should I need? I'm thinking of drilling that hole(s) at the back wall of my tank. Do I need to build a box for this? again my tank was 72"Lx18"Dx19"H. Please elaborate.. <Thank you for this reminder... am going to put a reminder on my laptop and finally (! he writes with conviction) produce some sort of general, definitive piece on marine aquarium plumbing (no applause please). Yes, to respond to your queries, there are quite a few seminal factors to bear in mind with the making of a tank overflow... for instance, to use an after-market "box" or to drill a hole/s... in the back, bottom? How many? What size? Most folks here (WWM) seem to be "rather" negative toward hang-on boxes... I am not so much so... with larger systems, employing two such devices virtually assures that one will have one going all the time... Holes in the tank? Most people are better off with ones in the back (or sides) rather than through the bottom... just something about gravity and the propensity for wet floors here... The placement of holes should be down a couple (as in two generally) inches from the proposed water level (this can be "adjusted" with threaded elbows on the inside of the tanks bulkhead/thru-hull fittings being turned...) Size? As large as you think you'll ever want to accommodate water through them... there are tables for such configuring, though, other important factors like "horizontal run" and induced drag are rather difficult to elaborate here/now... and "when in doubt, up-size" should be a guide/spiel. Do you know much re quieting down the at times incredible "gobbling" noise of such plumbing arrangements? There are a few techniques here... but suffice it to state, the larger diameter fittings and plumbing directing water from your tank to out... are easier to fit with noise-reduction. In your circumstances, I would look around for another glass shop... 3/4" holes are not of much use in a six foot long system... I would go with at least two 1 1/2" overflows (near the back corners... and likely two or three 3/4" returns... spaced about equally in the upper back. Bob Fenner>

Re: overflow topics Hi Bob! I have contacted somebody to make that hole for my tank over flow and do the plumbing inside the tank as well:) But slight problem here, How can I haul this six footer tank?.. eerk!  The place was bit far from home, Hoping to find somebody here to lend a truck! <Ask the folks who will do the work... they may have someone who will come to you... to your door/tank service... Alternatively, perhaps a local fish store can/will help you out with the haul> Any way let's skip that thing and got some questions here.. I noticed a lot them complained about those bubbles observed at their tanks/sumps produced by the over flow and return, is there any threat for this such thing? <Mmm, yes... some embolism possibilities. By and large you want to reduce the incidence of fine bubbles getting into your pump mechanisms> If so, any tips to avoid this problem? <These are posted on WWM> By the way Bob, I haven't made any move to start my project yet. I'm waiting till late November which my wife promised to plunge in for a salt water tank and I'm so excited, yet she was hesitant to let go the beautiful Flowerhorn whose occupying the tank. Here's the funny part, She snapped "what's next, a whale?!". Bob, I just want to gather all the vital information I can reap through your input way ahead so that when the time comes specially purchasing, ready and armed with your  valuable information. Hoping for your patience here.. thanks Arnold Borja <Good to have your significant other involved. Do keep studying, making notes on what you'd like to do... and why. Read on the Net, books, magazines... and look into whether there is a marine fish club in your area. Would be very beneficial and much more fun to have a local "guru" to look over your shoulder, show you about. Bob Fenner>

- Can't Drain the Tank Quickly Enough - Good evening, I was recently given a 75 gallon tank and wanted to set it up for saltwater. It had 2 holes drilled into it, a 1" bulkhead and a 3/4" bulkhead I was told that the 3/4" should be used as the return to put the water back in the tank. <Is pretty standard.> Now the 1" should be used to drain into my wet dry, right? <Yup.> I put in my surge 6000 (600 gph)  pump and it pumps the water out of my wet dry faster than gravity can drain the tank. All I have on it is a stand pipe (in other words just a pvc pipe up to the top of the tank). Do I need to have an overflow box? (it sure would take up a lot of space)   Should I just drill another 1" hole so the water would drain faster? <You might want to, if only for redundancy, but it occurs to me that something else may be wrong. I ran a 75 gallon tank with the same outlet and intakes as you describe and ran a pump in the 750 GPH range on the tank all day long. Do look to eliminate any 90 degree elbows or restrictions in the 1" line coming out of your tank.> Any help would be greatly appreciated. Armando <Cheers, J -- >
- Can't Drain the Tank Quickly Enough, Follow-up - So is an internal overflow box necessary? <No.> I think that since I don't have an overflow box, that it could be the problem. <I don't think that is the problem.> Or is it ok just to have the PVC pipe all by itself the top of the tank? <I would install some type of screen onto that pipe so that no fish get sucked in.> I also attached a picture <Cheers, J -- >

Bulkheads in tank with built in sump Hi all- Bob and Anthony enjoyed hearing you speak at the IMAC. <cheers, Andrew... it was a great time for all of us :)> I am being aided by my LFS but I am about to drill the bottom of my 65g acrylic tank and wanted a second opinion.  The back wall of my tank has a sump built into it (IFS). That's where the protein skimmer and return pump are located- I threw out the bioballs.  Well after adding an upstream refugium it became more imperative that I make some plumbing changes.  The third section of this in tank sump has about 5 inches of water covering two Rio 1700s.  So I have now bought an Iwaki MD 55rlt it will pump water into my main tank thru two outlets and into the refugium.   <very nice> I was going to try a J tube to get water out of tank but now I plan to drill and add some type of Rubbermaid container as a proper sump.   <whew! avoid siphon/J tubes at all costs... risky in the long run> So the question is will two one inch bulkheads drilled in the bottom of the tank flow enough water into this new sump?   <not sure... you need to add up the numbers on your plumbing size and run plus elbows, etc to calculate head and actual water flow... then compare that against the mfg  specs for the bulkheads sizes you choose to rate them. There are calculators for this on the big message boards like reefcentral.com and in fine books like Escobal's "Aquatic Systems Engineering"> The refugium is 27 gallons so with 90 gallons of display water I'd like to use as much of the Wake's flow potential as possible.  I have seen one inch bulkheads rated from 300 to 1000 gallons/hour. <there is no prayer of a 1" bulkhead coming anywhere near 1000 gph. 300PGH is the safe number bandied about which I agree with... and they can go as high as 600 PGH although quite noisy at that> Should I be expecting the low value because my bulkheads will be located in a small section~roughly 4inx12in? I hope this makes sense-the sump built into the back of the tank always seems to confuse.  Basically I just want to be sure that my plan matches expectations before I drain, drill tank bottom, I have to cut stand too..., plumb everything well you know Alright thank you very much and sorry I if I'm making a simple question way too long. Andrew <no worries, my friend... its a challenge at first, but worth doing the math. My impression is that 2 1" holes is nowhere near enough here. Larger bullheads or more small ones are needed here IMO. Kindly, Anthony> New tank isn't drilled (but overflow required!) Hello Bob, would like to know which overflow would be ok / compatible with the jewel Trigon 350ltr,and return pump required (Eheim 1260/ ocean runner 3500 or what do you advise! <I am much more "positive" re the use of such add-on overflow "boxes" than many of my cohorts here at WWM... for a system this size, for safety's sake, I would utilize two such devices... either tying in their discharges to your sump with a tee or allowing each to overflow separately>    Sump size is going to be roughly 27x15x18 with live rock, Caulerpa and then return probably housing carbon/ heater. Rowaphos I would  put under direct flow from overflow in a basket or something. Would you suggest any material different from above in relation to  sump, your expert advice would be greatly appreciated   Thank you ,I Smith, Preston, Lancs, UK. <All sounds about right. Bob Fenner>

Plumbing intake questions If you don't mind I just have a few questions. I just want to make sure I get as much as I can right the first time.  Also thanks for the quick response on the last questions I asked. My current equipment and setup...... - I have a 1" bulkhead on my sump. - I have a 3/4" return on my tank. - I purchased the Panworld/BlueLine 100PX-MD40R 790gph with 3/4" MPT in/out My questions are if I reduce the 1" bulkhead from the sump with a 1" x 3/4" reducer so that I can run 3/4" PVC from the sump all the way to the pump intake will that cause any issues?  Or will this be OK as the pump only has a 3/4" intake opening.  There will also be a Ball Valve and Union in the run. The reason I am wondering is because the 3/4" pipe will fit a lot easier with the room I am working with. Also I will be keeping the discharge/return of the pump at the 3/4". Thanks for letting me ask these questions as an experts advice is always welcome and a great resource. Hi, Your setup should work just fine. Depending on the output of your pump, you do in theory get less GPH with a 3/4" vs. a 1" return, but not enough to cause any issues. I did the same thing you're about to do on my latest tank. Jim

Plumbing Basics- HI :) <Hello! Ryan with you today> Thanks for all the great info on your site-it's awesome!! But, I think I'm a bit overwhelmed. <It happens!> I will be ordering a 65 gal( 48x18x17) with one back center overflow box and need to know where to have them drill the drain and how big to size it.  I have a 29 gal(30x12.5x18) DSB sump with about 4 ft of head between.  So'¦. If I need a flow rate of 1100gph(??), what size pump do I need if I have a 1 ½' drain?? <3/4 or 1 inch>  Do I have them drill it in the bottom panel for a stand pipe?( straight down means less noise right??)<Yes, in some cases.  You'll have to tinker with it to eliminate "slurping."> or the top back panel? safer if I don't trust the overflow box not to leak?) <Yes, also a possibility.> Also, is it safer to drill two 1' drains in the same overflow box? in case one gets clogged or perhaps a drain to a future mangrove refugium) <Yes, but I'd recommend you to feed a refugium with a bleeder from the return, to prevent flooding.>  This is too much like the SATS--I think my head is spinning!!!! <Ha!  Geometry DOES come in handy...> Aquariums seemed like such a relaxing hobby <So they say...Diagram your plumbing out, and send it in.  I'll have a look and make some suggestions.> ;) Dazed and confused, Jennifer <Half-Baked, Ryan.  Just kidding.>

- Bulkheads - Hi Guys, I am starting a 180 gal. reef. My two corner overflow are 2". Last time I wrote I was having problems with water draining fast enough. So a added two 1 1/2" bulkhead on the back wall of the tank and two 1". My two pumps equal to 5100 gal. /hr. Now when I turn the pumps on I hear a loud sucking noise from the 2" overflow. Do I still need to add more bulkheads? <No... the sucking sound is just what happens when you have a large amount of water passing through them... air is being pulled down with the water.> I want to avoid dialing back the pumps since water entering the tank goes thru a manifold. My tank is still in the testing stages so I am flexible. Also what is the typical flow rating on these bulk heads? <A one inch fitting should be able to move 1500 GPH peak... reality will be somewhat less. A 1.5" bulkhead should be able to handle about 2500 GPH max.> What would the proper size sump be on a tank this size? <As large as possible - you've got a lot of water in transit and you'll need room to have a working sump and somewhere for the transit volume to go when the power shuts off.> Thanks for you dedication to this site. Sincerely Stephan <Cheers, J -- >

- Overflow Size - Hello everyone. <Hello.> I have a quick question. I would have posted in the forum but it appears to be down right now. I have upgraded my pump to a Quiet One 6000 and have put all the pumping into place. I have a 55G tank and a 10G sump. Now I was wondering what size of an overflow would I need? I currently have a H.O.T overflow box with a 1" and 1 1/2" U tubes to move the water between the boxes. I have a 1" drain hose in the back box. I currently have to use a ball valve to throttle back the pump because my drain can not move enough water. My current box is 5" across 7" deep and 3" thick. I was wondering if I increase the drain from 1" to 1 1/2" would that be enough? <Yes, that would make a big difference.> I am currently looking at building an overflow setup that is 15"x8"x4" and using either a 1 1/2" drain or two 1" drains. <Either would be adequate, but you also might to think about two overflow boxes which will give you the right amount of drainage and also redundancy should one of the two develop problems.> I will be using two 1 1/2" U tubes to move the water between the boxes. Could you give me your ideal on how many drains I would need and what size. <Two overflow boxes, each with a 1.5" bulkhead would be perfect.> Oh and the pump will be moving about 943GPH with my current plumping. Thanks. <Cheers, J -- >

Overflow from Down Under - 6/24/2004 Bob: I recently read a response from you on an old FAQ titled "Overflow tower with "over-under" divider".  Here is an excerpt: "...you says a better overflow tower had an over-under divider in their fronts to return water to the sump from the bottom layer of the tank water. <Yes... to bring at least some, if not most of the water from the system's bottom water layer... to the sump, outside the tank>".  Questions (Sorry, I started with only 3): 1) I gather from the current "reef-ready" overflows, that this still holds true, yes? <Yes> 2) On these overflows, the bottom slots will pose a problem/be covered by a DSB in display, won't they?   <Mmm, not if they occur above the DSB area> 3) I am considering a custom drilled tank (around six 1" bulkheads on a 6' long 125gal), with the "internal skimmer box", a la Anthony Calfo.  Is it an issue having all water overflowing from the top of the tank?   <IMO/experience it is better to have water from both the surface and near bottom> 4) If so, is this "problem" solved by vigorous flow? <Could be> 5) Do you think six 1" bulkheads will allow me to do almost anything in this tank, flow-wise?   <... I'd likely go with three 1 1/2" (pi R squared... actually much more surface area, flow capability...) than the six one inchers... one right, left, about middle> 6) Would you have a different drilling preference (to be prepared for the most flow-demanding livestock in the future)? <As stated above, yes... and consider the alternatives to the ends/discharges... there's a larger SCWD on the horizon (per chatting with Bob Stern at Interzoo in May...)...> 7) If you were to suggest larger bulkheads, how much more noise are we talking about here (or am I at toilet-flush level already)? <There are various means to quiet down these downspouts... aspirators and open tees to the surface principally... worth looking into and employing> I am pleased to be able to state here that your website and books have been a boon to me and so many others.  Your contributions have saved untold lives, and I am forever grateful to you and your volunteer crew for what you have provided.  Sincerely, Rich Licari <Thank you for your kind, encouraging words my friend. Service to you. Bob Fenner>

Proper size for PVC return 6/10/04 Sitting on the fence -- give me a push Hello all, I have conducted research on plumbing my new aquarium and have found conflicting advice (go figure).  I desire your varied opinions.  In plumbing an Iwaki 30rlxt (1' input and 1' output) with approximately three 45 degree elbows, one 90 degree elbow, 1 foot of horizontal run, and 5 feet of vertical ascent, should I use 1' or 1.25' PVC for the output?    <either will be fine... the difference is negligible> The research indicates that the more elbows and horizontal run I have the larger the diameter the better; but the weight of the increased volume in the larger diameter pipe increases back pressure in the vertical run thus potentially negating any benefit.  A call to Iwaki customer service left me believing it was a toss up. <I agree completely> Thanks, Mike the neurotic <that may be true too ;) Anthony>

Bulkhead Diameter Hi Guys- <Hey there! Scott F. your guy tonight!> I have just purchased a new pump, Amp Master 3000, and am worried about the necessary size for the return piping to the sump. I currently have one overflow box in the back corner with a 1.125 ID bulkhead (using a Durso standpipe to keep things quiet). In order to handle the 3000 gallons per hour, I am having another overflow box installed in the other back corner, but not sure of the size piping that I need. I am certainly not an engineer, but found some gravity flow equations on the web that gave me an overall minimum ID of about 2" taking into account the 3 foot vertical drop and 3 foot horizontal length to the sump. Does this sound about right to you? <Yep. I'd go with 2 inch standpipes for this type of flow> Therefore, would a 1.5 inch new bulkhead be enough with the current 1.125" in the other corner, or should I go larger? Thanks for all your help, Steve <Larger cannot hurt, but I believe that 2" would be the way to go! Regards, Scott F.> 

Plumbing! Help =) 4/13/04  Hello Wet Web Crew, Your site is awesome!  <Thanks! Glad you enjoy it!>  Just wanted to run some plumbing parameters by you. My new tank is a 120R (48x24x24) FOWLR to be any day now. There is a trapezoid in the back and will be three holes drilled. The drain will be 1" and the two returns will be 3/4" run off of two Sedra 9000's (900GPH each). One return will be directed to the front face of the trapezoid in the upper part of the tank, and the second return will split to each side of the trapezoid in the middle portion of the tank. Now for my questions:  <Sounds good, but if it isn't too late, I would size up to 1.5" drains and 1" returns. You can always adapt down the size if you want, but it is really hard to go back and make them bigger. Unless you have really dramatic head losses, you will be running very close to the capacity of your drains which makes it very hard to sleep well at night.>  1) Is the drain bulkhead size sufficient? (I plan on placing a Durso standpipe in and his website recommends 1" drain bulkheads.) Will there be sufficient drainage for this size tank?  <They will probably be sufficient, especially if using a "Durso standpipe", but I personally am a fan of overkill (within reason).>  2) Should I place more than 1 drain bulkhead?  <Definitely yes! Particularly if you are using 1" drains, I would only count on each drain to be able to handle the flow from one pump. Be sure that you got the correct impression from the Durso website. I suspect that the recommendations there would have fallen in line with one 1" "Durso" per each 900gph pump.>  Should I move up to the Sedra 12000 x2 (1200 GPH ea)?  <If you like, but if so, I would definitely size up to 1.5" drains.>  4) What do you think of the return configuration?  <Sounds fine. You have to compromise between evenly distributing flow and having enough velocity to produce good turbulent flow. Using some kind of flexible (aim-able) outlet like loc-line adds a lot of flexibility.>  Thx again, Tom <Always a pleasure! Best Regards. Adam>

- Plumbing and Overflow Design - Hi all, I am in the process of building a 110 replacement for my 65 gallon reef tank and I wanted some sanity check on the plumbing I have planned, I have read the FAQ's until I can no longer make sense out of it all so I thought I would just ask outright.  Background information: 110 tall tank 2 X 250 Watt HQI XM 10000K 100 Lbs Fiji LR Tomato Clown and Black Sailfin Blenny Planning a 40 breeder tank as sump / refugium 1000 Turboflotor Classic. I have a 48 X 18 X 30 All-Glass tank that I have had (5) 1" bulkhead fittings fit into the top rear of the tank 3.5" down from the top.  My plan was to use the middle 3 for an overflow from a culture shelf type of weir that will be 4" high and extend 3.5" out from the back wall and 39" across the tank back. Question 1: should the front spill edge of the overflow wall glass be smooth or are "teeth" serving some purpose I do not know about. <The teeth act as a coarse filter - saving most fish from a free ride to the sump.> Question 2:  both remaining 1" bulkhead fittings are for return plumbing and I am thinking using one for a manifold around the top of the tank with 4 or 6 outlets, and the second diving down and feeding another form of manifold just above the 5" DSB Southdown topped with aragonite special seafloor mix to keep the deep tank flowing. I will be reducing flow with the elbows and such, but hopefully delivering the flow more precisely were it is needed <I think I missed the question there...> Question 3: Pump output recommendations at about 5' of head (30" stand and 30" tank) thinking about 1200 to 1500 GPH to allow some SPS or should I go all the way to 2200? <As much as is practical.> tank to house combination of  Zoo's, Mushrooms down deep and  Xenia, and a few  SPS up on top. (Not sure if I'm ready for SPS) <Until you have the metal halide lighting, you will not be ready.> Question 4: do you have a link to a good picture of an internal overflow / culture shelf picture? <I am not aware of any... perhaps one of out readers will send in a link.> Thanks for your time and patients with us and our thousands of questions, if not for you folks I would have hung up this fascinating hobby/obsession long ago and missed out on all pleasures it brings into my life. Forever in your debt, Todd <Cheers, J -- >

Going Larger - UPGRADING 4/2/04 Hi Guys,  Short question here. I currently have a 100 gallon reef tank using a refugium for my filter. (I mainly keep tangs and a few corals). I wont go into lighting etc.. as my question in basically on the new setup I am getting. I just ordered a 200 gallon oceanic tank (8 ft long x 24 x 24). The tank has a double overflow boxes. Should I run one large sump that I wouldn't be able to get out easily once it is in or should I run two sumps - one on each overflow box? <If you run two sumps, you must connect them.  If you run two unconnected sumps, and one of the pumps stops, that sump will overflow since the other will continue to pump water up to the tank while part of it is draining to the sump with the broken pump.> Also, what do you think about adding a few holes in the upper back for additional pumps coming from the sumps or closed loop for more flow (instead of power heads?) <Extra holes are a great idea for many reasons, but it would have been very advisable to order the tank with the holes pre-drilled.  Keep in mind that wherever you drill the lowest hole, that is where the tank could potentially drain to in case of a leak.  Placing the holes up high and then plumbing down to where you want the inlet or outlet to be is much safer.> I am looking at Nemo or Shea pumps for my main returns and Mag 24 or something for the holes in the back instead of the power heads. Any other tricked out ideas I came to try them.  Thanks, Steve <I am not familiar with Nemo or Shea pumps.  Do consider Sequence for their high flow rates and low noise and power consumption and better reliability compared to equivalent Dolphins.  In general, I prefer external only pumps like Iwaki over submersible types like mag drives for better reliability and less heat transfer.  Best Regards.  Adam> Bulkheads/Wet-dry/Drilling Questions I'm new to this whole plumbing and wet dry filter thing and I have a few questions before I start to do any alterations to my tank. I currently have an acrylic TruVu 55 gallon tank with a Magnum 350 for freshwater fish. Today, I bought a Del Rey 125 wet dry filter and was planning to use the overflow/u-tube set up that came with it. Fortunately, there was not enough room to fit the overflow box. So now I plan on drilling and adding a bulkhead. Is a 1" bulkhead large enough?  <I would use at least one (likely two and tee them together) 1 1/2" bulkheads> The wet dry came with an Aquaclear 802 powerhead (up to 400 gph). How big should the hole be for a 1" bulkhead? <Measure the outside diameter. Likely an inch and a half> I was thinking about placing the bulkhead in the top center of the back. Is this a good location? <Mmm, no. IF only one intake, make it at one end and return the water at the other. Better to draw and return at both ends> Also I was thinking about keeping the Magnum running along with the wet dry or would this be too much filtration? <No> When I drill, do I have to empty the entire tank, or can I just remove half the water to give myself enough room to work with? Thanks for your time. Thomas <Better by far to do the drilling with the tank all the way empty... Not hard to do (in retrospect), though daunting for first times... do have someone help you who has done this before and run the drill slowly. Please read over on WetWebMedia.com re: the use of a smear of silicone on the threads and gaskets of your through-puts. Bob Fenner>

Overflows Hey guys! I have a custom tank in the plans. Its a 125 gallon. Dimensions are 60LX24DX20H. My LFS is having it built and drilled. I do not know much about how big or where to drill so I was relying on them for information. Before I went through it, I wanted to run what they told me to you guys to see what you thought. They recommended that I have 1 drill in the center of the back wall. It will have the wall thing built around it (don't know what it is called, but it has the groves in the top for the water to flow through).  <An overflow "tower" or raceway. Not necessary if drilled through the back... you can use commercially made thread in screens instead> Should the holes be in the back or on the bottom of the tank? <Almost always in the back> This (wall) will have these grooves on three sides. I was wondering if it would be better to have 2 holes drilled, one in each back corner but being in the corner, each would only have 2 sides of the grove things. I would also appreciate an opinion for a pump. I want a good one so I was thinking about Iwaki. but unsure of how much pump I need. Thank you for any information you can shed on my situation.  Rob <Rob, your answers and much other needed input on these matters is archived on our site: www.WetWebMedia.com Go there, use the search tool, or better, peruse the setup area of the marine section. Bob Fenner>

Pump Size and Overflows Dear Bob and Crew, <Scott F. your Crew member today> How do you guys rate the Mag Drive pumps in  terms of reliability? <I find the new Mag Drive pumps to be quite reliable> I was thinking of getting the MD24 for a 75 gallon with 55 gallon sump. I was hoping 4, 1" bulkheads could handle 1900 gph. Do you think I'll be ok? <I think that they will, <<No... RMF>> but with little margin. You may want to go for 1.5" overflows to be safe. Regards, Scott F> <<Yep... RMF>>

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