CircMarFAQ3

FAQs about Circulation in Marine Systems 3

Even flatfish need good circulation.

Circulation Hi, again. I have a 75 gallon reef tank, with a Yellow Tang and a few other fish. For circulation I have 2 Rio 2100's (I know, but I've had them for a while) <I know they have a bad rap, but I also know of quite a few people that have them and have never had a problem. I would not recommend someone go out and buy them, but I would not tell you to throw them away either.> on one side, at the top and bottom of the tank and shooting sideways, and a Rio 2100 on the other, also shooting sideways. In the middle, at the top and back of the tank, I have a 300 gph powerhead shooting out towards the front. <Ballpark of a little under 2400 gph total.> Flow seems good for the corals (they seem happy), but the fish seem to swim upstream quite a bit. I don't think they're struggling, but I'm wondering if I should lower the flow, or change it somehow. I don't want to have to replace the pumps I already have if I don't have to, and I don't know if I should lower the flow, since the corals seem quite satisfied. Is it too much, or do I just need to distribute it better, or...? Thanks for the incredible help you provide reef enthusiasts. :) Arthur <You are welcome. -Steven Pro>

Re: Flow/Circulation Recap - 75 gallon tall reef tank, 2 Rio 2100's pushing water from one side, 1 Rio 2100 pushing from the other, 300 gph powerhead pushing from middle back of tank forward. Corals like it, but the fish seem perturbed. I didn't think that I have too much flow (and based on your response to my last e-mail, neither do you), <Correct> but the fish (a powder blue tang and a clown fish) spend much of the day "leaning" into the current, looking like they're swimming upstream. They seem to seek out the pockets of the tank where current is strong. <If they seek out these places, why would you think they do not like it? There are obviously some low flow areas they could escape to if they wished.> The clownfish especially looks overwhelmed, I guess because he's so small. They look uncomfortable. Is this an issue, or can I relax and let them be? Arthur <Please relax. This is nothing for them. -Steven Pro>

New tank circulation dispute, please help settle! Hi Anthony I hope you are all well at WWM. <very well my friend... cheers from across the pond!> I have a problem with ordering a new tank because the FS owner doesn't agree with what I am asking for in the way of circulation. <hmmm... that's interesting...heehee. Is he the anti-capitalist?> What he is recommending is 4 1/2 * the volume <weak... bordering on dangerous for corals> and then make up the rest with some sort of wave making arrangement that then costs another 300+ pounds sterling (464+ US Dollars). <wow... he's either a crook or incompetent or both <G>. Wait a minute... maybe he's brilliant... a wavemaker is a lot more expensive to sell you than a single recirculating pump <G>! Wave makers for larger tanks in particular are poor choices for creating water movement and way overpriced by any standard. Tell him that I said, his "mother was a hamster... and his father smelled of elderberries!". Lets hope he is a Monty Python fan too :) And then tell him to read this article: http://www.wetwebmedia.com/circmarart.htm > I have told him that you recommend trying to get at least 10* the tanks capacity through the sump. (After reading your article on Circulation) <awesome> and that I would like my tank to be able to accommodate at least this through put. Am I misunderstanding you here? you do say 10*Vol through the sump instead of powerheads don't you? <absolutely. I'm specifically saying to avoid powerheads if at all possible. They are junk technology but a necessary evil for some. A single large pump on the sump running a teed manifold (nozzles) topside (like described in the article) is perhaps one of the very best ways to provide water flow. Some aquarists that don't want high flow through their pump drill 2 holes in the main display for a closed loop in the tank run by a second external pump. The two holes can be placed anywhere and simply are plumbed together with a pump inline. This second pump never needs primed and is fairly low maintenance (do have shut offs and quick disconnects on either side though for removal and pump cleaning without draining the tank). There is much chat on the big message boards by the advanced aquarists on this strategy. I like it just fine. External pumps are longer lasting, cooler running, more energy efficient, and aesthetically discreet and hidden altogether... everything that powerheads are not> I suggested he might look at your site , I am including his response below enclosed in this type of brackets {{ }} and would really appreciate your comments on the content so that I can feel better able to answer his objections or tell him the suggested resolutions. <indeed our pleasure> He makes it seem like I'm asking for something ridiculously over the top and that I'm asking for excessive noise. <then you are talking to a man that hasn't seen or done it successfully before <G>. Do share your plan or sketch with us here before you commit to pumps and holes, etc. Better yet... do you have a fax number we could exchange faxes at? I can send you a sketch that way> The tank size is 5ft*2ft*2ft and will hold 125 Imperial Gallons (150 US gals approx.). Could you tell me what you would have drilled in this tank and the through put you think is reasonable for me to ask for! <absolutely... if AMP master pumps are available... do consider. Else, a Japanese made Iwaki in the 6000 liter per hour range would be excellent (just avoid the dual pump/400 series... they are the only noisy ones in the bunch). The size of the holes to be drilled is up to you, my friend. Just check the bulkhead specs for flow tolerances. We want to exceed the pumps maximum capacity as you can imagine. If you want to do that with 5 holes for 25mm pipe, or just 2 or three larger holes (40 mm)... that is up to you. Somewhat of a personally preference here. Am I correct in recalling that you have my Book of Coral Propagation as well? If so, look at the illustrations in the early part of the book for modifying an overflow for a long drawn discreet shelf (page 42/43... and if you don't have it... I'll figure out a way to e-mail it <G>)This is tremendously quiet and drastically improves the quality of overflowing surface water. If you prefer to have the floor drilled instead, look at the illustration on the next page and modify that with a Durso standpipe... see here for instructions: (http://www.rl180reef.com/pages/standpipe/standpipe_menu.htm)> Maybe suggest a pump that could achieve it for me. LFS response: {{after our discussion of last week, I read the articles within wetwebmedia.com and whilst they are of some interest I must say some of the information is very misleading, as it does not specify whether the information is in regard to trickle filters or natural reefs in most circumstances. To give you some idea of the impracticality of flowing 2,500 gallons per hour through the sump, your aquarium would require a minimum of 4* 40 mm return pipes to sump to cope with 11,000 ltrs, this would therefore require 4 overflow boxes. The noise would be unbearable. <this is the first problem... standing overflows (as opposed to having the back wall drilled with the internal overflow shelf... rather silent) are inherently noisy if they are not fitted with a Durso modification or like design. At any rate... sure, just drilling 4 holes in the floor of the aquarium is very noisy... but we're talking about professional installations here instead.> please follow this link to the site of a very experienced hobbyist http://website.lineone.net/~espsrg/circulation_.htmi look forward to hearing your reply. Danny}} I followed this link and got the impression that this aquarist was in agreement about lots of flow through but not through a DSB which I wanted to have in the sump. How would/should I handle this. <ahhh... agreed. The DSB in the sump is an issue. Strong flow will make this challenging. There are in fact advantages to upstream refugiums rather than downstream/under sump... do consider (no plankton shear however small that may be, it becomes an aesthetic focal point... perhaps keep jellyfish or mangrove trees or something exotic in there that cannot be in the reef proper, etc). But yes... I missed the DSB in the sump bit. If its important to you... you'll have to compromise and get flow through other means like a closed loop pump in the display and a smaller sump pump, or top-mounted pumps (Gemini, Tunze Turbelle)> I hope you don't mind me burdening you with this <no burden at all! It is our pleasure and duty to help> but as I am having the tank and stand made to order I want to get it right and this chap is starting to worry me with his insistence about unbearable noise. <understood and agreed. Jenny, let me suggest that you find a few local aquarists to visit and see their tanks in operation with this style. Just post an open query on reefcentral.com stating you are a UK reefer from so-and-so and you're looking for a shared opinion from another local. Its a huge message board with a lot of nice folks. Seeing systems with Durso overflows and /or closed loop, 2-pump reefs will put your mind at ease and also guide you to make the very best pump and hole choices. Do you know of any local aquarium societies for like fellowship? Tell you what... I'm going to e-mail my book distributor there in the UK and see if he can help direct you locally> Is there a minimum number of baffles/dividers needed to reduce noise or something else that needs doing? <nope... the baffles will not likely help.> Many thanks for your valued advice Many thanks Jenny <And let me say again in parting, if there is a fax number that I could send you a sketch too... I will draw up a design specifically for your tank size. Else I will need to get the sketch scanned by a friend and try to e-mail it to you. Have you had a chance to glance at this illustration?: http://www.wetwebmedia.com/plumbingmarart.htm it has some fundamental elements (some not all of use to you). Best regards, Anthony> Jenny Nunley

Re: New tank circulation dispute, please help settle! UK reefing Hello again Anthony, Thank you so much for your speedy reply and willingness to help me with my tank problem. The only fax number I have at present is my work's fax which is ################ you are welcome to use this I understand it is left on all night so should be o.k. If you would send me a sketch of what you would do I would be really grateful. <I just sent over several pages with a sketch of the sump fed by a horizontal internal overflow (with a profile of this apparatus on the last page) and of an optional closed loop pump as well. This one or two pump system can easily replace all other pumps for water movement if you'd consider the manifold system also sketched on page two (profile page three). This is an incredibly inexpensive way to get incredible fine tuned random turbulent water flow without any visible artifacts like powerheads in the tank display. Aesthetically very clean> I could rethink the DSB idea if you think it has an adverse affect on the sump through put, I thought it was needed to complete the nitrogen cycle. Also I have no preference on where the holes should be drilled i.e. bottom/back of tank, I will go for the back if that is the best method. <I think the top back is best and quietest. You may use 1 or 2 large holes per 1500 gallons per hour, or 4-6 smaller holes (25-35 mm) scattered across the back. It makes little difference either way... as long as the mfg spec satisfy the flow you choose to run. Simply pick whichever you can get drilled easier with available bulkheads> I am afraid I don't yet have a copy of your 'The Book of Coral Propagation' because I haven't yet heard back from the UK distributor you told me about so I can't yet refer to it. <I can send you one direct if you like as well... $45USD (about 29 GBP) Thanks again for your help, the FS will have to wait until I know what to tell him I want. Thanks again - Jenny <do advise me if the faxes aren't legible (or intelligible <G>). I will be glad to re-fax or explain. Also see this link for an elaborated view of possible reef plumbing components: http://www.wetwebmedia.com/plumbingmarart.htm also... here's an excerpt from my book describing the internal overflow shelf diagramed in the faxes: "Overflows drilled into an upper sidewall of the aquarium or culturing vessel are perhaps the most common. They are easily managed and require less strategy in planning. They are generally smaller and less obvious than internal siphon overflow boxes and stand pipes. They are also the least expensive way to modify an aquarium for overflow. Holes are simply drilled with an appropriate hole saw for glass, acrylic or masonry and a plastic bulkhead is fitted. Businesses selling aquaria and ponds generally have the ability to order or complete hole drilling for customers. Careful consideration of desired water flow and pump size will determine the number and size of holes drilled for overflow. Distribution of holes along a given plane is of little significance regarding the quality of effluent water captured. Some aquarists prefer to bunch multiple holes together; others spread or split them apart. Ultimately, sufficient water flow through the display should make the debate over the distribution of holes a moot point. What does impact the quality of water captured by an overflow is surface area. Imagine if you will, two overflow boxes each with the same sized feed that continues on a downstream path (a one inch pipe, draining to the sump, for example). If one box has a larger "mouth" (the linear surface area that the water flows over), the effluent water displaced will be spread thinner across the spillway than the smaller box. Put another way; let's consider the same situation on an aquarium with two drilled overflow holes. If we know that the flow of circulating water can be managed by two holes operating at half capacity, then the addition of two more holes (for a total of four) should permit them to operate at a level half again as much (specifically at one fourth capacity). The surface area was doubled, so the "thickness" of effluent water overflowing was cut in half. The concentration of over flowing water is particularly important for the capture and export of proteins and other targeted matter known to migrate to the surface of seawater. The "thinnest" surface water captured will have the greatest concentrations of targeted nutrients for export by a protein skimmer or other filtration component downstream. Beyond drilling extra holes for the over flow of water, a very simple modification to an internal overflow can be made to improve the quality of water captured. The greatest benefit will be achieved on overflows that run the length of display walls that have been drilled with holes. This can be simple and made discreet, particularly on the plane of an aquarium or culturing vessel that is not viewed through (such as the rear wall). Although the same volume of water will flow through the same given number of bulkheads had they been unassisted, the incorporation of a long, shallow overflow box will spread the given flow of water quite thin over a greater surface area (see the first illustration for this section titled, Hiding Unnatural Features of a Display). While the new feature is aesthetically more prominent than bulkheads alone, it can be hidden in a most unique and useful fashion. By extending the floor of the overflow box beyond its vertical wall by a few inches, a functional shelf is created. This shelf is in a position to receive strong light and current which is ideal for some coral species. Suitable corals may be placed on the shelf and rotated in programs of culture or allowed to encrust for aesthetic purpose. Aquarists should construct the internal overflow box as long as functional and aesthetic preferences allow. Please refer to the previous illustration on page 42 for a profile of this feature." <best regards, Anthony>

Overflows Can you gave me any information on the Stockman overflow I have been told it works better than the Durso. RGibson <Cheers, Ralph! How the heck are you my friend? You've caught me in town and on e-mail for once <G>. I have been traveling so much... a great time, but I'm getting behind on phone calls and friends. Regarding the Stockman overflow... I have no personal experience with it at all. As usual, we'll post this for responses. Best regards, Anthony>

FOWLR: to bubble or not to bubble Gentlemen (no gentle ladies yet, right?): <Oh no, there are some Gentlewomen around here somewhere! Not this time though!> I have asked this question before, but I was not specific about my setup. I have a Power Sweep at one end of my 55gal FOWLR. Is it better for it to create tons of bubbles in the tank (venturi-style), move water with no bubbles near the surface or move water from deeper down? <Better to move the water at the surface with no bubbles.> I have no problem with the millions of bubbles or the noise, but only if it is beneficial. <Could be harmful> I do not have a skimmer yet for my 6-week old system. I remember reading somebody saying that would make a difference (as far as the need for bubbles). Is that true or did I misread? I have read the FAQ's and they were helpful (as usual); I just need something a little more dead-on. Thanks, Rich <Get that skimmer ASAP Rich, it will help aerate and clean-up your water. Micro bubbles can be problematic for some fish. Craig>

Solution - Turboflotor 1000 and bubbles in sump/tank I was able to get rid of 90% of the bubbles. I "invented" a device. Maybe I should market it! Since my overflows use 1" PVC and output from Turboflotor are 5/8", I made a bubble trap with a 2" piece of PVC with cap on bottom. I made it about an inch higher than normal sump level. I then inserted this into a Marineland filter material (filter in outside). I then flow water from overflows and from skimmer into top of the PVC traps (overflow and skimmer returns extend about 2/3 of the way down into the traps). The water flows in, cascades out of top (which dissipates some bubbles) and then flows through filter material. The filter material removes most of the remaining bubbles. This has eliminated 90% of the bubbles - the only one that remain are extremely fine and evidently pass through the filter material. There are still bubbles but they are greatly reduced. If I could find a finer filter material I am sure I would eliminate almost all of them (something like a sponge-type filter with a 2"-2.25" opening in middle to fit 2" PVC trap). <Emperor Aquatics makes micron filter bags that maybe just what you are looking for. They are extremely efficient at trapping debris, but must be rinsed out almost daily, for fear of becoming a home for nitrifying bacteria.> Will the remaining 10% bubbles and of very fine/smaller nature pose much of a danger now? <Probably not much> They are hard to see anymore and most evident under the 2 x 96 compact fluorescent lights. You can't see them coming out of the return anymore - before it looked tons of dust blowing out into the water. They are very very fine and smaller now and don't seem to stick to everything anymore. - Mark <Do look at the micron bags as another option. If you clean them regularly, they are very effective at removing large amounts of detritus. -Steven Pro>

Water Turnover Question Hello again! <Hi there! Scott F. with you tonight> I've been reading through your pages and pages and pages of FAQs and I must say its very impressive, I especially like the stocking recommendations, fewer fish then most people want but I agree 100%! On to the point. My tank is a 125 Gallon, with about 20 gallons of sump I would guess. I am using a RIO 2500, hooked to a spray bar. How much do I want to turn over the tank for fish only? The return is coming through a spray bar I made myself, could this be limiting how much return the pump gives me as well? Do I need more flow??? How much should I be turning over a fish only tank? Most info I find is for reefs. <Not sure of the output of the Rio- but I like to shoot for 10 turns an hour, even for FOWLR> Also, I am planning to upgrade my SeaLife 75 skimmer to a AquaC 180. Is it easy to inject ozone into this AquaC skimmer? It has no venturi and no air stone, I want to be sure it will work before I spend the $350 on it! It was a huge headache and hassle making the ozone work with the SeaLife skimmer, I would rather avoid that in the future, I would of course buy the carbon outlet collection cup for the AquaC, just curious how you get the ozone INTO it! <Do contact Jason Kim at Aqua C. He is a great guy, and will be glad to talk you through the process. They have a great web site, too, which may provide some help> Also I asked about my Redox last time I wrote you guys, and you said let it be and let it do its thing. Its been 2 weeks now, and my Redox is now up to 148 (from 135), in the last 3 days it seems to be going up about 2-3 a day. Is this normal? Does it really take this long to raise? <A rising Redox is always good. How slow or fast depends upon the conditions within the tank> I have also, since then removed all my sponges and filter pads from the tank, thinking they were leaching mass amounts of nitrates into the tank. The prefilter in the overflow box had never (in 2 years) been replaced, I just kept rinsing it. I really can't figure out why my water quality isn't that good. I just purchased a Nitrate test kit, so I will test when I get home, I suspect they will be high. <Good move removing the pads. Do test the nitrate regularly> Oh yah, Ammonia is .2 (I think because the tank sat empty for a week then I added a fish a week ago at least I hope that's why) Nitrite is 0, pH is 8.4, salinity is 1.024, and the temp. sits steady at about 81.7 (though it was down to 80.6 this morning so I just bought another heater, 1 200watt isn't enough for this tank). <Ammonia is a sign that something is amiss! And you probably should shoot for around 500 total watts of heaters> Attached are some pictures of the setup, any info you can give to help me provide a healthier living space for my poor puffer and future residence would be great. I plan to add 2 or 3 more fish to the porcupine puffer, some type of large angel (juvenile though), maybe a wrasse, and something else nice but not to huge. Below is a list of what the pictures are of. Which reminds me! Last thing :) I've had the puffer for 2 weeks almost, and he never comes out when the lights are on. All day and evening when the tank lights are on, he sits under a rock and hardly moves (sleeping), then as soon as the lights go off, out he comes...even at night he's not real active, he pretty much just paces up an down in the corner of the tank, but he does eat (krill with Kent garlic Xtreme added to it) at night when he is out! Any idea what's up with this? He twitches and spins sometimes too, but not a lot. <Well, the ammonia reading might have something to do with it...> 125gal_salt = tank as a whole Overflow = Overflow box in the tank, not sure on its GPH, its an older AMiracle overflow. Spraybar_return = my spray bar with a RIO 2500 on the other end, I believe its 1/2" PVC with small holes drilled in it, not 100% sure on size of the PVC though. Sump1 = my main sump w/ bioballs and heater in it. Later added a 2nd sump to hold more water and spread things out (AquaC will go here later I think) Sump2 = My addition sump, and Ozonator (useless pic other then shows the skimmers to small) Collection Cup = My homemade collection cup, holds carbon to filter ozone from the air (1 hour at home depot and $5) Sump2_Inside = Useful picture, shows my skimmer, RIO 2500 return (has an elbow on the end for when the water level gets low), Also homemade carbon filter for ozone skimmer water return, and a sponge that does nothing, its only 1/4 under water, I may just take it out tonight it may be a nitrate bed?? <probably, if not cleaned> Sump1_Inside = Heater, a Minijet powerhead just moving water so it doesn't stagnate on the surface like it was, my ORP Redox meter hangs over the overflow drain tube. Overflow2 and Overflow3 = My older style AMiracle overflow box from the outside, with sponge removed. Any idea how many GPH this does? Will I need a new one if I upgrade to a bigger return pump? or a second one? <Check with the manufacturer to see how much flow it can handle, and modify as needed> Thanks in advance for your help! You guys are great!! <And have fun! Good Luck!> Mark

New Tank I am setting up my second tank. It is a 125 gallon tank, six foot long. I have 4.5 to 5 inches of oolitic sand and built a hang hood with three 175 halides and four 110 watt fluorescents run off an IceCap 660. My question is regarding water flow. I have a 600 gallon overflow plumbed into a 20 gallon tank with a Turboflotor 1000 and a Rio 3100 return pump. <Two problems as of right now, the siphon overflow and too small of a sump. This 20 gallon tank is going to give you problems trying to balance between top off and overflowing.> Right now the return pump is choked down as to not overflow my tank. <Well, the Rio 3100 is rated for 900 gph at 0 feet, so this is probably doing no more than 500 gph is your tank at full throttle. You have it slowed down, so you are way under the recommended 1250 gph total circulation.> It feeds a four foot spray bar that is just under the surface of the water. I can't really see the effects of the flow because all there is is sand in the tank. <If this is not fully set up yet, please stop and correct. You will have a good bit of work right now (shoveling out sand), but it will save you countless hours of work and aggravation later.> My rock will arrive Wednesday the 30th. <It sounds like you have a busy weekend cut out for you.> I want to make this a SPS tank. <Definitely correct your basic problems. See if you cannot jam something closer to 40-50 gallons as a sump under your tank. Also, I would look for two external pumps able to handle 1200 gph at zero head each. Lastly, get rid of the siphon overflows and get your tank drilled to handle 2000 gph as a minimum. Look at the multitude of plumbing and circulation articles and FAQ's on www.WetWebMedia.com for more information.> What can I do to increase water flow to recommended ten times the tank capacity? <The ten times turnovers recommendations are for fish tanks or reef tanks with LPS and soft corals. If you are going hardcore SPS you should try to attain 20 times the volume turnover/circulation.> Should I add a 800 gallon overflow and put my 3100 returning this water through another spray bar and add a 2500 for the other overflow. <See above> I don't mind the look of the bars. In time they should just blend in. <Agreed> I am not wanting to use powerheads as they are a lot of work. <Agreed again> Also is 150 pounds of live rock enough. <Should be fine.> And any ideas about aquascape. I was thinking of three little islands so I could see more sand. <That sounds fine, too.> My other tank is rock across the back and I don't want them to look alike. Thank you for your time and help. <You are welcome. -Steven Pro>

Live Rock & Tiny Air Bubbles Hi Bob, <Steven Pro in this morning.> Two quick questions for you. I just set up a FOWLR aquarium, 200 gallons, I run it with a 100 RLT IWAKI pump. I have noticed what looks to be thousands of very tiny air bubbles that makes the water not look crystal clean (it's been three weeks since set-up so not any detritus on the rocks or aragonite gravel). The flow from the IWAKI is very strong, don't know if this is what's causing it but I didn't want to lower the flow as I was told keep maximum flow. <These microbubbles are generally caused by one of two things. Either the pump is drawing in bubbles from the sump or their is a pin hole leak in your return plumbing that is acting like a venturi. First, I would see if the bubbles are originating from the sump. Excess bubbles from the skimmer or caused by crashing water from the overflows are two main problems. If not, I would check each joint, smearing with Vaseline and see if the bubbles disappear. Once you isolate which joint has the hole, merely clean up and reseal/reglue the joint.> Second question is I bought some nice (lots of coralline algae) live rock and have had it for about two weeks, it seems to be turning slightly white (dead looking in places). I run mini-compact lights for about 6 hours a day. Is there anything I should be doing to encourage the coralline algae growth. <Maintaining calcium and alkalinity levels while minimizing other nutrients is key.> Thanks for your help. Your site is great. Joe Jugovic <You are welcome. -Steven Pro>

Circulation Situation Greetings <Scott F. tonight> Sorry to ask so many questions but I am therefore I ask. I have a Supreme Mag drive 950 in my 55 gallon sump which is in the basement as my return to the main tank which is a 75 gallon it travels vertically 6 feet the return line that is. I have checked the flow from the overflow back to the sump as 690 gph. I used a 5 gallon bucket to test I got one gallon per just under five seconds. first question is . Is this sufficient? second I was thinking about building a somewhat closed loop around the tank with tees in all four corners with flexible ball joints to point flow where it is needed will the mag drive 950 still be ok or should I put a dedicated pump for my closed loop. I of course would prefer to utilize the 950. By the way I am in the terrible diatom phase with my tank (brown patches on everything) rock, glass, powerheads. hope it doesn't last long :( <This, too, shall pass. Maintain good water quality, stay on top of changes, feed carefully, test...you'll be fine!> Thanks for everything, keep up the great service you provide to all us green horns. John S. <Thanks John, I learn more every day thanks to fine folks like you!>

Kalkwasser & Wavemaker Hi Anthony, I hope your doing well. <with hopes that you are the same, my friend> I'm on a weeks vacation, so as usual I am fiddling with my tanks. I have two questions. (1) I still can't seem to get your Kalk slurry correct. (read your book instructions twice) On my 125 with 35G sump, If I use B-Ionic, I can keep my calcium in the 340-360 range at a DKH of 10 or 11. <actually... that just about perfect if you choose to have the higher dKH (12 dKH max). Else, let your dKH fall towards 8-9 and let Ca climb to 400-425 ppm. It makes little difference either way. All is good if both are consistent and stable> However If I want to use Kalk and Seachem buffer, I can't seem to change the Calcium at all, it just keeps dropping until I go back to B-Ionic. <have you checked to see that your magnesium isn't too low? It needs to be at least 1000ppm. Better perhaps around 1200ppm or a whisker higher. If you have low Magnesium... your not going to get high Ca. Mag should be about 3X Ca levels> Every day, in the AM I stir maybe 1/4 to 1/2 teaspoon in 1 or 2 cups cold R/O water for about 20 seconds and add it to the sump. My PH goes up a little usually about 0.1, but the calcium doesn't seem to make it into solution, I don't see any precipitation) and if I measure a few hours later there seems to be no effect. Any ideas what I'm doing wrong. <hmmm... the AM is dangerous in the big picture for dosing unless your lights don't come on for 7-10 later. Kalk is always to be dosed at night right after lights go out> (2) I want to add current to my tanks starting with the 125. I looked at a wavemaker from Red Sea, but am leaning towards the Ocean currents Oscillator. My feeling is that I could put two oscillator into the tank attached to power heads. What do you think? <I think that all wavemakers are a complete waste of money. They wear pumps down and starve thanks to flow when pumps are staggered. Its best to run all pumps full time in convergence to produce random turbulent flow> Thanks Larry P.S. someone who owns a store close by and I believe to be very knowledgeable says he prefers to drip Kalk. He thinks the sudden increase in PH, or more accurately the sudden localized PH increase has a detrimental effect on the fish. <dosed in a strong stream of water it is no worse many other aspects of husbandry. Serves the greater good for many> He thinks the Slurry you refer to is mainly for reef only systems or corals farmers. <I think he must be a man that has never tried it before with a simple pH meter... OR... he has the patience of a saint for dripping and a tank with modest calcium needs (fish only). I also suspect that has never had a system that needs more calcium than a saturated drip can provide> I don't agree, and dripping is a big pain in the a%&. <yep :) Best regards, Anthony>

Re: this is my problem and I don't know what to do. (Circulation) Anthony that's cool. One thing on the detritus though. I have 4 powerheads in the tank now. everything is on, I have 2 Rio 1400 and 2 Rio 800's each in its own corner of the tank, 3 inches from the water level. <do reconsider the powerheads... they cause too much heat. If you have a sump, it is usually less expensive and more efficient to run one large recirculating pump than a small one with powerheads in the display. See diagram here: http://www.wetwebmedia.com/plumbingmarart.htm> thing is, if I let the heads hit the bottom, the sand will float to the water column... what do you think I should do? <the best with powerheads is usually to aim them opposite of each other to create random turbulent flow. Indeed... flow in one direction will stir up sand badly> the skimmer is in the sump and that I don't think the detritus "overflows" to the sump. <yes... a common problem. Do experiment with adjustments to the flow with the powerheads... aim them in different positions to reduce the chance of detritus accumulating> Francis. PS: ill check your website re your book ok. <thanks kindly!> have you ever been in manila?

Re: New Hobbyist Do you think I need any form of aeration other than my Red Sea protein skimmer? <Likely not as long as you also have vigorous circulation.> I am storing my sea water. I just have the water in buckets. Is it necessary for circulation or other things? <Aeration and heating to match the display is needed. -Steven Pro>

Return Flow Bryan again. I bought Anthony's book and have been really enjoying it. But I do have a couple questions. Getting ready to start a new reef tank in my 75 gallon. Going to go with some corals. As far as return water from the sump, what are some suggestions you might have. One idea I have is on each end of the tank have a spray bar facing each other, causing a turbulent flow. Anthony made mention of a manifold around the top dimension of the tank with tees with moveable elbows to vary the flow. How exactly does this work? <You build a loop around the top of the tank using PVC pipe. Every so often you add a T in the loop. From that T, you reduce down to a movable elbow or a section of modular pipe (say the loop is out of 1" PVC and the movable outlets out of 3/4" or 1/2"). Modular pipe is like the stuff Oceanic Reef Ready tanks come with. The little black interlocking pieces that can swivel around.> Any suggestions? Thanks, Bryan <You are welcome. -Steven Pro>

120 Gallon Tank Flow Rates Greetings to the WWM staff, I am setting up a 120 AGA that will be used as a reef tank and have just a few questions about the flow rates that the tank can handle. The tank measures 4 X 2 X 2 and has 2 overflows, one in each rear corner. The overflows appear to be drilled to accept a 1" drain and a ?" return, respectively. <Fairly standard> I have a custom acrylic sump in the basement with a capacity of 90 gallons and will be pumping back up to the display. I will calculate the required head pressure and size the pump accordingly, but I lack some required data at this point and cannot arrive at a logical conclusion that is based on fact. I intend to fabricate some Durso standpipe devices so that the wife won't complain about noise and such coming from the overflows. <Good idea> I also would like to run (2) ?" Sea Swirl return devices so that I have a very nice and turbulent water flow in my display. Since the tank will be dedicated to SPS, I think they will appreciate the water movement. <Agreed> How do I calculate to total capacity, expressed in GPH, of the 2 Durso standpipes? They will be 1" of course <Do double check your design. I believe Richard recommends using 1 1/4" or 1 1/2" PVC for the drain with a reducing fitting at the very end.> and I can size the pump accordingly but I certainly don't need a bunch of water on the floor in room where I will house my display. Many thanks in advance for your replies. Jason <Good luck to you. -Steven Pro>

Re: too much water circulation? Thank you for your response. I followed your advice, so I contacted the people from Little Giant, and they told me what you said "this pump is not intended to use in marine aquariums". So I return it and change it. Thanks. <You are welcome.> Just to give some practical things that I observed with my reduced flow. Maybe 2-3 days after the flow was reduced, the hair algae started to grow over some parts of the rock, then Cyanobacteria appeared in spots over the sand, the skimmer started to produce just green tea substance instead the coffee product. It is amazing how fast the environment can be corrupted when just one (and so important as the water movement) condition is out of the right performance. <Appropriate flow is a critical component.> Today at night my tank will receive the benefit of a new pump 850 gal/h @3' ahead (my tank 50 gal.) <Sounds good> Greetings <Have a nice day. -Steven Pro>

Water movement in clam tank Hello everyone at WWM, <Howdy> I am planning an 85 gal. flatback hex tank (48 x 18 x 24), and the critical species that will inhabit the tank are Tridacnid clams. Can you help clarify my confusion over the flow rate for the tank? <I'll try> Daniel Knop's book on giant clams states that "we have to do with much less performance when keeping clams. . . that is, five times the aquarium volume. . . seems reasonable to me." (pg. 147) That seems pretty low. <Mmm, it's okay... given "complete" movement of the water (little "dead areas")> I am trying to keep the specs of the tank as close to standard as possible to keep the costs down. The tank can be constructed with up to four 1" drains and four or six 3/4" returns connected to 3/4" centipede return fittings for directional control. With this setup, the flow rate should max out at 1200 GPH--yes? <Okay... bear in mind this is "real" flow rate versus an estimated value. In actual practice almost no pump installations yield near rated flow rates per interval> Now the $6,400 question(s): Is this flow rate appropriate for a clam tank? Too much? Too little? <About right. Most Tridacnid species, individuals will put up with, even enjoy greater water movement... as long as it's not directly blasting on them continuously> Any wisdom you can offer would be greatly appreciated. Your Web site has been a valuable resource for me in properly planning this tank. Thank you all! <Glad to hear this. Bob Fenner> Jeff

Re: Porcupine Puffer (actually water movement, pH: marine) Anthony: Thanks for the help. 2 more follow ups. 1.) is there a source written or electronic which directs how much water flow different species of fish prefer. <good question, but no authoritative work that I am aware of. Much of it is anecdotal or inferred by study of where the fish comes from on the reef... lagoonal and open water species preferring quiet flow, herbivores like tangs from reef crests and surging areas like stronger flow, etc> 2.) My PH is 8.3 middle of the day but my dKH id 10.4 and my calcium is 360. <all quite fine... let the ALK fall a little if your like and you'll be able to bring that calcium up a little. Small matter though> How do I push my PH up without sending the alkalinity through the roof. <ease up on buffer and use more Kalkwasser instead... that will raise pH and calcium levels> I am using ESV two part solution for buffer and calcium. <a fine product... my favorite brand of its kind> Thanks again for the help. James <with kind regards, Anthony>

Too much water circulation? Hi everyone! How was your weekend? <Too short!> A few days ago, the pump that I was using to return the water from the sump to the main tank failed. So in that hurry, I took one of the power heads from the main tank to replace the one who failed. Obviously the power head doesn't "pump" enough water so I went to buy another. The only pump I could find (suitable to be inside of my house without the night noise) was a "Little Giant" 5-msp (sump pump (submergible) which can propel 1000 gph @10' head. <Are you sure this is saltwater safe? My guess is no.> My tank is only 50 gallons, so that pump can drive 20 times the volume of my tank. It is too much? <No> I made a kind of flute with 4 nozzles pointed to different directions in order to create turbulence. Right now I only have 3 fish (2 damsel, 1 yellow tang) some hermit crabs, 4 turban snails, 1 brittle star, 40 pounds of LR, and a few polyps. My intention is to create a good place with good water flow and light to keep a reef tank. <Sounds like you are on the right track, but do double check that pump, though.> Thanks for your response, Carlos <You are welcome. -Steven Pro>

Re: too much water circulation? Thanks, for your prompt answer. I am not sure too! I asked to the guy from the Pump store and he told me that there is no problem with the pump, but in the catalogue says that if the pump will be used with water having a high mineral content (hard water, and marine water is), a condition called "galvanic corrosion" may occur. What is galvanic corrosion? I am going to call the guy from the store to ask a change. But at least you said that the volume of water is not too much, so I am in the good way. <You might double check the Little Giant website, http://www.littlegiant.com/> Thanks again, Carlos <Good luck to you. -Steven Pro>

Water Flow Hello, Quick question? I have a 55 gallon tank with a 1 inch bulkhead in the top left corner going to a 10 gallon sump. I know I should probably have a bigger sump but I can't get anything bigger under the stand. I am using a RIO 2100 for return at about 4 ft. I also have a powerhead 402 up in the top right corner and I would like to do away with the powerhead. <excellent and agreed> Could I add another 1 inch bulkhead and upgrade my return pump. <absolutely and a great idea!> If so what size return pump would I need and on the return could I add a T and split it to each side of the tank. Thanks <the pump size will be limited by the two drains... I would recommend at least 3 holes and preferably a 4th. Then you could run a pump of nearly 1000 GPH nicely with a teed return. Best regards, Anthony>

Re: Cloudy Water? (Mmm, water qual., Kalk, calcium, circ...) Robert, <still Anthony Calfo here... Bob has yet to return from Indonesia> It is my understanding the reason you drip Kalk at night is because of the pH differential between day and night. <essentially yes... it tempers the night drop in pH from respiration> I purchased a Ph meter last week, <an excellent investment!> calibrated it and found that my Ph was around 7.98 to 8.00 (early lights on) I buffered and dripped Kalk until it read 8.20 (don't worry over about a day). <good... but no higher than .2 per day> That has been about 5 days or so and the ph has not varied more than 0.05 (day or night ( I don't sleep much)). Since my Calcium has never been what I consider high (300 to 350) I've been dosing pretty steady to try to get it up to 400 and as you mentioned earlier might be the reason behind some of the cloudy water! I'm so confused. LOL <heehee... yes, the whole Ca/Alk dynamic can be frustrating!> My new protein skimmer has been delayed and won't be here till Friday so I'm thinking about washing out the air stone on the little Berlin and see if I can get it to work until then. <agreed> Good news is I found my bubble problem. I had a network of valves etc off my pump (both on the pressure and suction sides), which facilitated in my water changes (was pretty cool) and replaced with plastic hose. All bubbles gone!! <awesome!> I might try replacing the pressure side valve assembly so that I might pump water from the sump to the tub for my water changes! That came in real handy. This might sound really basic but when you say "aerated" are you talking about placing a air stone in my water storage or a power head to just move the water around? <simply air bubbles my friend from an air pump. If a water pump is used instead it should be placed on the bottom of the vessel and pointed up at the surface to facilitate gas exchange> I would like to say thanks again for all the help you are providing, it is not going un-noticed. Best Regards, David <it is very redeeming to hear... thank you :) Anthony>

Circulation versus Higher Temps Gentlemen: <<Greetings, JasonC here...>> Firstly, I would like to thank the person that helped clarify my grounding probe question that was answered by Andrew. <<!? oh... perhaps Anthony?>> My query today pertains to a pump that I recently added inside my tank. I have a 125G FOw/oLR acrylic bow. It stands 27 inches high and has three front panels. The two side panels are 12 inches wide and the middle section is 36 inches wide. I have a sump that has a wet/dry, UV and protein skimmer. I use a Rio 2500 that returns water to the tank from the sump, with the bulkhead positioned on the bottom in the middle of the tank. While I noticed that circulation was vigorous on the bottom one-third of my tank, algae would build up toward the top. I thought that adding a pump inside would create additional circulation as well as cut down on the algae. I added a Rio 1700 (with appropriate filter attachments) to the top right front corner of the tank. This created some nice circulation and appears to keep the water cleaner. The fish, especially the tangs, really enjoy the added water movement. However, I have noticed that the water is warmer. I am wondering if it could be attributed to the added pump. <<Oh, for certain.>> My tank is also against a west-facing external wall that does get hit by sun in the afternoon, and it has been warm in So Cal the past few weeks. <<That could do it too, but a Rio 1700 is a fairly strong pump and capable of bringing up the water temperature a degree or two or even three.>> I have read some posts that debate the virtues of an inside pump versus increased temps. To test if the higher temps are due to the added pump, I disconnected it this AM to see if I notice a decline in the temp. I was reluctant to do this as I liked the additional circulation. <<I say circulation and consistent temperature are more important - you didn't mention what the actual temperature of your tank was, so it's kind of hard to tell you if it's too hot, or not a big deal. Even if your tank was 82, it wouldn't be the end of the world - just so the tank doesn't drop to 78 at night, you'd be fine. 78-80F is the ideal range, but I would certainly take 82F as a side-effect of vigorous circulation.>> Your comments and thoughts are appreciated as always. Thanks, Mitch <<Cheers, J -- >>

Re: Circulation versus Higher Temps Thanks, Jason, for your prompt response! And, my sincere apologies to Anthony, as watching the NFL highlights and hearing the name "Drew" Bledsoe must have messed me up! <<Oh well...>> I am sorry that I failed to mention the temperature. It is 82F to 83F during the day and seems to remain fairly consistent during the night, with perhaps a slight decline as evidenced by my readings first thing in the morning. I should mention that the temperature would approach 84F in July and August before I added the Rio 1700. The fish seemed to behave fine which would support your consistency theory. When the temp would get that high, I would have a fan blow over the sump which seemed to drop the temp by a degree or two. <<Yes, the fan-plan works well... I do this myself as well.>> OK...please tell me if this is the correct approach. I will continue to run the Rio 1700 and monitor the temp. If it nears 84F, then I will use the fan to take it down a notch. But, I do not want the temp to drop too much too soon as this could be harmful for the fish. <<This might just require that you keep the heaters pumped up to 81-82 so that things stay nice and warm... or perhaps 'consistent' - that is the buzz word of the month.>> Thanks, Mitch <<Cheers, J -- >>

Powerheads Bob, a question about powerheads. <<Bob's not here, man. You get JasonC in his stead.>> I 46 gallon bow front marine tank. I have a Aqua Clear 300 on one side of the tank and I also have a Aqua Clear 400 on the other side of the tank. My ecosystem also has a Rio 600. The powerheads face each other to get a turbulence kind of effect and the Rio just agitates the surface. Do I need additional powerheads because of the bow front? <> Thanks <<You are welcome. Cheers, J -- >>

How to get powerheads out of my 55 gallon tank I would like to do away with powerheads in my 55 gallon reef tank. I took your advice and did away with the tidepool overflow box and drilled the tank. It now has a 1 inch bulkhead with a 1 1/4 hose going to the sump. What do I need to do to get the correct amount of water flow though the tank without using the powerheads? <It depends on your corals kept, but anywhere between 550-1100 gph of return water.> I have a RIO 2100 for water return and I know that is not big enough. I would like to have water flow coming from both sides of the tank. <The best thing is to build a PVC loop around the top of the tank with four or more outlets to distribute the water flow. -Steven Pro>

Water flow and other questions Bob, Anthony, Steven, you've all been a big help so far answering my questions as well as the countless others. <<Must be why it's in my bucket now... JasonC here at your service.>> Thanks! I have a 72g reef in its 4th month. I am noticing red Cyano on my DSB in the corners where I assume the water flow is lowest. I have backed off on feeding (roughly 1 cube frozen mysis or krill every other day -- the active consumers are 2 Perculas, 2 Chromis, 1 Banggai cardinal, and 1 scooter blenny, and 1 peppermint shrimp) and recently added a fresh shipment of Nerites, Strombus, mini Turbos, bristleworms, micro hermits, and sand bed clams from IPSF (to the preexisting population of Turbos, Trochus, Cerith, and red hermits) in the hopes that some increased activity in the sand might help. I am also thinking of altering my water flow, and I have a few questions for you. <<Shoot...>> This is an Oceanic RR bowfront with the return (Eheim 1060) in the upper left rear corner, aimed at the right side glass. At the upper right rear is a MJ 1200 opposing the return and alternating 40 seconds on and 40 seconds off (Natural Wave) <> Both upper left and right front corners also have MJ 1200s connected to the Natural Wave, aimed along the front glass and alternating every 20 seconds. The flow is nice and turbulent for the most part and, at any given time, is theoretically between 900 and 1200 gph. In the past I have tried aiming the PHs slightly downward but it ends up creating sand drifts across the DSB. Is there a way around this? <<Put down a layer of heavy, more coarse substrate.>> Should 1 or more PHs be moved lower in the tank? <> Should I disconnect the wave maker, or upgrade to a more powerful return pump? Or is the Cyano just a stage that will pass? <<A little of both, but I think by manipulation of the powerheads, you will eventually land on the magic placement combination. You just want to avoid those laminar flows.>> FYI, water specs: 80 degrees, SG 1.026, ph 8.20, Alk 3.4 meq/l, Ca 420 ppm, Iodine 0.06 mg/l, Mg 1380 mg/l, NO3 2.5 mg/l, PO4 0.03 mg/l. Tank is skimmed with AquaC EV-120. Could lighting be an issue? Bulbs are all new, 2x175w 10000K MH (10 hrs) + 130w 7100K PC (12 hrs). I realize that this is a complicated question and I hope I was descriptive enough for you to visualize. <<No worries.>> As always, I really appreciate you advice and all of the great information on the site. Thanks again! <<You are quite welcome.>> Ed Marshall, Austin, Texas <<Cheers, J -- >>

Water flow and Algae Anthony you and I have talk about water flow in reef tanks, and you have said many times about having outlets on all side of the tank. <yes... not written in stone but nice for many aquarists trying to achieve random turbulent flow without investing much time or thought into the process> In my own 180 gal reef tank I pump 2000 gal per hour out of 4 outlets in the back of the tank. But if all reef tanks large and small had also 2-4 outlets in the front of tank it would keep algae down much lower then they have now. <agreed> Keeping algae moving would give the p skimmer a better chance to remove them from the tank. <exactly... detritus stays in suspension for removal by skimmers, etc and the algae themselves are often inhibited by reef type flow... they generally favor calmer waters (warmer temps and higher nutrients too of course)> "Dilution is the solution to pollution" <Amen!> Have a good day RGibson <kindly, Anthony>

Re: pH decline, Demerits of Powerheads Friend Anthony <cheers, Bob> Thanks for the suggestions. I think that I will try first with the larger return pumps; <excellent> I am a bit concerned about powerheads in the tank as I have read the many horror stories on the web site regarding animals sucked into the suction strainers. <yes... so many disadvantages to powerheads. Heat transfer, longevity, shock hazard, etc> Thank you for your patient advice. While very little in the way of compensation, please do accept that you provide a real service to the many out there like myself who labor mostly blindly. <it is our pleasure and purpose but thank you for saying so, my friend> A little story: I started the marine aquarium as an ex-freshwater guy who liked the pretty saltwater fishes. After failing pretty miserably several years ago with a fish only tank, gave up completely. Read some more recent books, including Bob Fenner's, and noted with great interest the improvements in lighting, natural filtration and so on. Made the investment "one last try and then I quit!". Have now run the reef for about a year, having survived numerous close brushes with ignorance induced failure, but have dodged the bullet with the help of yourself and others dedicated to the trade and hobby. My greatest reward (and this should be for you as well, as a participant) is that now when the neighborhood children come over to our house, which is often as we have two boys 10 and 12, they all immediately go to the reef tank. These children, who can rarely stay still for more than 30 seconds, are immediately captivated in the mystery of the reef and I have seen them sit for over an hour in front of the display. <outstanding.. indeed a huge goal for us all: education of people to higher awareness, admiration and respect for the environment> I have directed several to your site. The rewards of the keeping of aquariums are many, but this is the one that I find the most satisfying. My point in the story is that you provide the support that makes this possible, so I hope that you share the joy as well. Best Regards Bob <thanks kindly... best to you. Anthony>

Pumps Hello, I have been researching water circulation for my aquarium. I have a 55 gallon aquarium with a 15 gallon sump. My return pump is a Rio 3100 with about 4 feet of 3/4 inch PVC attached to a spray bar. I noticed that there are some spots in the tank along the back wall on the sand that don't get much circulation, right below the spray bar. I was thinking of using a Y to split off the return, use maybe 1" or 1 1/2" pipe and raise the spray bar to the surface instead of being right above the sand. Then have the other section of the Y split off to the corners to act like two powerhead facing diagonally to the front center of the tank. <It is probably better to create some sort of manifold with valves to adjust how much water is directed to each outlet.> From everything I read, the two streams of water will clash and cause a variation in water flow, so that there might not be anymore dead spots for red slime to gather. Will this work? <Sure> Will the increase in pipe size allow more water to flow? <Yes> The sites I read talked about not restricting the flow with small pipe. (But they were talking about Dolphin pumps with a 1.5" outtake) The outtake on the Rio 3100 is about 7/8". What is your advice. I am trying to minimize pumps to minimize heat. <A good idea.> Thanks, Daniel <You are welcome. -Steven Pro>

Re: pumps, Water flow, Manifolds and Power Heads Hello again, I was wondering if you could give me some clarification on the manifold concept. Is there some site, book, etc. that might show examples or plans. Thank you, Daniel <cheers, Daniel... I describe such a manifold in my first volume of the Book of Coral Propagation (excerpted below) and will place an illustration in the next volume (I'd offer it now but it hasn't been drawn in AutoCAD yet). Hope it helps... Anthony Calfo> "My recommendation for water movement in display aquaria is the employment of a large external pump (or more than one if necessary) driving a discreetly plumbed manifold above the display. A large pump can simply feed a single line of pipe that runs in a closed loop at or just above the system's water level (imagine a pump fed circuit of ?" pipe, for example, fitting the entire inside perimeter of the aquarium). Around the perimeter of this manifold are to be numerous teed-outlets that can be adjusted, restricted or turned off. Swiveling 45-degree elbows work well for flow adjustments when fitted into tees glued at a slightly downward angle (in case of a leak or nozzle expulsion). The construction can be completed simply and inexpensively with PVC materials and has many benefits. Several "nozzles" may be directed to converge in the water column to produce random turbulent circulation that is nearly as ideal as surge/wave motion but far less complicated to produce. The option of using flexible, interlocking pipe nozzles makes fine-tuned control of a manifold quite easy for aquarists with a larger budget. The absence of any powerheads in the display is an obvious aesthetic benefit. Despite their popularity, I do not recommend powerheads as a primary source of water movement. The disadvantages of powerheads include: the impart of heat to the display from submersion, increased maintenance (and increased risk of killing/damaging livestock through screened intakes or nitrogen-generating, fiber pre-filters), aesthetic detraction (ugly!), expense of quantity for commercial applications compared to the delivery of flow by large dedicated pumps, significant risk of electric shock by virtue of their construction (most do not have grounded plugs, and concerns have been expressed about stress from their operating noise underwater with magnetic impellor fields. The absence of dump buckets or surge devices above the display is equally convenient and practical. While dump and surge devices produce very good water movement, they require greater maintenance to build, install and maintain. The fast accumulation of salt creep from the splashing water and bursting bubbles on bulbs and lenses is destructive to the fixtures and the quality of light reaching invertebrates. One or two large external water pumps, instead, dedicated to water circulation will satisfy most displays smaller than one thousand gallons. Any extra cost incurred on initial purchase is easily recovered by pump durability and longevity (sparing the inconvenience of replacing cheaper, submerged power heads and any livestock lost due to their failure). The cost of operation is relatively inexpensive on magnetic drive models (beware of operating costs on direct drive pumps, however). My suggestion may well apply to the masses with generalized needs, but there are certainly exceptional cases where this application will not be the best or most efficient choice. Ultimately, aquarists must experiment and observe the health of their specific corals in display and propagation to determine nirvana with water movement." [Book of Coral Propagation, V1 Calfo page 157]

Re: pumps, Water Flow and Manifold Hi Mr. Calfo, Sorry to keep trying to clarify. I found a couple websites, so I could try seeing what this might look like. Here is one site, the best I could find. http://www.hawkfish.org/snailman/diypumpmani.htm So, are you meaning that a single pipe would run up to the aquarium, where it would connect to a version of the above that encircled the top of the aquarium. <exactly... in a loop at the top of the aquarium to distribute water flow more evenly from all nozzles (as opposed to a single pipe like they have shown... which would allow more water to flow through outlets nearest to pump in the line)> There would be t's like on the above, with a gate valve or something similar to open and close off flow then at the end of the gate valve there would be a positional 45 degree elbow to direct the flow. <overall yes.. although the gate valves on each outlet (between the tee and the positional/swiveling 45) might only be appropriate for a larger aquarium. For smaller tanks (under 200 gallon) you may want to simply look into the various fitting and adjustable nozzles available with the snap-tite/lock-tite style plumbing (black interlocking and adjustable plumbing available from MO aquarium supplies) and some LFS> I hope I have the idea now. I am not very mechanical, but I think I understand know. Please tell me if I am right and where I went wrong. Thanks, Daniel <right on Daniel... I apologize that I don't have a handy diagram or photo for you. Best regards, Anthony>