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FAQs about Circulation in Marine Systems 5

Related Articles: Circulation, Submersible Pump Selection, Efficiency and Price Assessments by Steven Pro, Inexpensive Wavemaker Impressions, by Steven Pro, Plumbing Marine Systems, Holes & Drilling, Aeration, Water Flow, How Much is Enough, Powerhead Impressions by Steven Pro, Marine System ComponentsRefugiums, Central FiltrationFlow-through Live-holding Systems, Refugiums, Business Set-Up

Related FAQs: Marine Circulation 1, Marine Circulation 2, Marine Circulation 3, Marine Circulation 4Marine Circulation 6, Marine Circulation 7, Marine Circulation 8, Marine Circulation 9 & FAQs on: Rationale, Designs, Pumps, Plumbing, What's About the Right Amount, Troubleshooting/Repair, & AerationPumps, PlumbingMake Up Water Systems, Sumps RefugiumsGear Selection for Circulation, Powerheads, Pump ProblemsSurge Devices

Many fishes that you might think of as slow-moving need a great deal of circulation

Circulation Dilemma <Hey There! Ryan with you> First let me commend you guys on a great site with loads of information, I never feel like I will get to the end of it! <A wealth of knowledge!  I use it everyday as well> My New - Future Reef Setup: CSL retrofit 48" 2x 175wt MH / 2x 65wt PC actinic 150g Perfecto 48"x24"x30" WxDxH tank viewable from both sides, but in wall Natures Miracle Pink Samoa Sand Amiracle XL Mudd Sump in basement (approx 35g?) (proposed) not placed yet: Kent Marine Bio Sediment 20 lbs Nature Miracle Live Sand 40 lbs 1400 gph 1pc Overflow w/ 2 outlets, plumbed with 2x Lee's 1" ID vinyl hose to basement sump. <Sounds sweet so far> Currently 1- 3/4" ID Lee's return from sump using Supreme Mag Drive 24 1" output reduced to 3/4" pumping from basement approx 14' high/head.  Ends in a piece of U shaped PVC with some Loc Line flex hose into tank. There is also an extra 1" ID vinyl hose from tank to basement as a spare. <Skimmer?> All the hoses are new and in floor/wall behind sheetrock, and more hoses cannot be very easily added (although nothing is impossible). <I understand> There are no powerheads currently. <Remedy this> My question is this enough circulation for my tank if not, what can I do to upgrade? My thoughts: I can return the pump or get another pump and put it on the 1" spare back to the tank, however I am not sure the 2- 1" ID hoses can take the flow since I read a 1.5" hose has a max flow of 600 gph. Which I am to assume I have max 800 gph at most.   Although I fear in the 1 or 2 turns in the wall behind the sheetrock, there may be some tight spots where I cannot guarantee 1" each. <Pump should be fine- What you really need is a few powerheads aimed at each other for some sporadic water movement.  This will be of benefit to most marine aquaria.> I have been reading through the FAQs and it seems like the Iwaki's are highly regarded as well as Gorman Rupp pumps?  <Both a fine product> If I am to target a 10x changeover/hour that should mean about 150+35?=185x10=1800 gph at 14' head. <10-20 is recommended, you're on the lower end of the scale.  This is more reason to increase circulation in the tank itself> The Iwaki MD70RLT (1170gph) + MD 100RLT(1740) seem to be in this range.  Now my only worry is getting the water back down to the sump, as well as the 3/4" return back to tank. <Tinkering is the best part!> Is the answer to get my remaining circulation from a closed loop?  If so how much would you allot to each system? <I think you'll be fine as long as you can add some good circulation to the tank.  You may even want to direct the water upwards in an effort to keep the surface agitated.  Page 123 of Anthony and Bob's new book may be helpful in making your decision.  Best of luck! Ryan> What should I do? Thanks so much in advance, Alex Wu

Circulation Dilemma Revisited Ryan, <Here!> So is the answer to continue to use the existing setup that is only pushing a 2.7x turn per hour? <Sorry if I was unclear- You need to be at 10x for a reef.> If I look at the flow chart ( http://www.pond-o-mania.com/mag-drivestats.html) for the Mag Drive 24 at 14' head it's only pushing about 500 gph on my 150g+35g=185g setup, that's 2.7x turns per hour a far cry from the 1850gph for 10x. Therefore I should change my pumps to the Iwaki MD70RLT or the MD100RLT BUT will the water accumulate in the tank faster than it can come down the 2- 1" inner diameter vinyl hoses back to the sump??  It seems I can only move about 800gph back to the sump. <750 gph should be adequate with lots of circulation in the tank itself> Therefore should I target around 750gph (4x turnover) and then make up the rest in the tank with powerheads (for the remaining 6-16x turnover to add up to overall 10x-20x turnover)? <Yes, exactly> If that's the case then I wanted to use SCWD's and loc line attached to the powerheads and hide everything in the LR, does that sound right? <Yes, sounds great.> Your other comment regarding a skimmer, I was under the impression that a Mud filter/refugium with Caulerpa didn't require a skimmer (detrimental?)  Otherwise I have a currently running FOWLR system with a venturi skimmer that I am going to rip down and move all the LR and inhabitants over to this new house. <Actually, I was simply inquiring if you were planning on using a skimmer or not.  Many people have had success in skimmerless systems, especially when using Mud Filtration.  I'm just not one of them!> Thanks again, <Sure!  Sorry for the confusion> Alex Wu

-Extra flow = extra noise? Try a closed loop!- I have a 120 reef tank a mag 18 for a return pump with two overflows. I would like to know if a mag 24 would greatly increase the gargling sound in the overflow box. <Likely, but you'd be taxing the flow capacity of your overflows.> The reason for the upgrade is so I don't have to use power heads in the tank if possible. I would like to rely on my returns to do the circulation instead of the power heads. <How about making a closed loop with the mag 24? The pump would sit behind the tank on the floor with the return T'd off back to the tanks (on SeaSwirls if you can afford them). You can make a PVC inlet with a couple of strainers to draw water from the main and hide it behind the rocks. If this doesn't make sense, check any of the reef message boards and do a search on closed loops, they're all the rage! -Kevin> Please advise. Thank you in advance for your time. Regards, Cecilia

- Flow Rates - <Good morning, JasonC here...> I have enjoyed reading all the post and helpful answers as well as Bob Fenner's recent book.  I have a question about plumbing a 65 gallon reef tank.  First how can you determine the drainage capacity of a particular size bulkhead? <Somewhere, there is a formula but for the life of me I can't recall at the moment - if I recall, 1" is capable of 600 GPH, so 1.5" will be much more so.> I am thinking about using two 1.5" overflows in the upper back wall in one corner approximately 3" apart and enclosing them in a full size (tank depth) overflow box to increase surface skimming capacity.  The box would fill and then empty via the 2-1.5" overflows into the sump.  Does this sound feasible? <Sure.> From the sump inlet side I want to feed the skimmer then into the clean side and back to the tank via one pump.  Also from the sump inlet side I want to go directly back to the tank with one pump and split into two returns for basically a closed loop circulation as I would rather not use powerheads.  How does this sound. <Feasible, but you might want to at least feed the skimmer and closed loop from a settling chamber in the sump - water coming from the tank will have a lot of air in it which will make the pumps cavitate and in turn be less efficient and noisy to boot.> One of the most confusing parts of setting up my first reef tank is the plumbing to provide adequate flow and circulation. <I think you are on the right track.> Thank you very much for any advise. John <Cheers, J -- >

-Closed loops and PBTs- Hello to all at WWM: I have only 2 questions this time. I know you're going to say.......just two? Here goes: 1) I want to add more circulation to my existing 110 gal FO set up. Currently I am using an Iwaki 30 RXLT for my return pump from my sump. I have another Iwaki 30 that I wanted to use in a closed loop for circulation. The Iwaki has one inch fittings but I am not exactly sure how to get the water from the main tank to the pump. I will be using one inch flexible tubing but is there some type of elbow I need to go over the top rim of the tank? This I assume will need some type of strainer on the end.....any additional thoughts? <I've attached pictures of the gorgeous inlet to my closed loop that I made with a Mag 9. The mess of PVC parts not connected to a pump is the inlet which hangs on the back of the aquarium with the strainers hidden behind the rockwork. It doesn't have to be fancy, just make sure that the pipe is at least as large as the inlet of the pump so it doesn't get restricted. From the 3/4" inlet of my mag, I T'd it off into 1" pipe w/ two strainers. This way the flow is greatly reduced through the strainers; preventing anything delicate from being sucked up inside!> 2) I have a powder blue tang for just over 2 mos. When I first got him he was in my QT for 3 weeks and seemed to be doing well. I transferred him to my main tank and after one week......you guessed it...ich. I could not transfer back to QT since I was already using the tank for another "fish project". Anyway I decided to use hyposalinity therapy, which I have used in the past with great results. I reduced the SG to 1.009 at 81 degrees. I kept it at this level for approximately 4 weeks. I monitored my water parameters throughout the whole time (pH , etc.) I have been slowly increasing it and so far as of today it is at 1.017. All signs of if ich are gone, all other fish are doing well but my concern is my powder blue tang. My tang seems to have changed its feeding habits. It used to gobble up the Julian Sprung Sea veggies but now barely picks at them. The same holds true for all other types of food I give (Seaweed selects, flakes, mysis, clam, brine shrimp). The tang seems eager to eat but once the food gets to him he seems to just swim around and through it but not eat it. He is starting to get thin and I was wondering from your experience can/will the tang recover and start eating more? <Powder blues aren't the hardiest fish ever, as you well know by now. Since it still eats a little, I'd pick up an anti-internal parasite food (such as Jungle's Pepso Food) and feed that to it for a while. Otherwise there's really nothing else that can be done besides making sure that every piece of food that it eats is chock full of vitamins.> By the way, I have a few tanks including 2 reef tanks for many years but was very reluctant to get the Powder Blue. This was one fish I have always wanted but knew the difficulty involved in keeping it. I broke down and got one and have been struggling for the last 2 months. Right now it's become "personal". I am pretty confident, with the help of WWM, we can get this fish back to health. I am just not sure if I am on the right track. Thanks so much for all of your valuable time. <Good luck with that beautiful fish, hopefully it will make a turn-around. -Kevin> Gene

Water Flow Hello Gage, <Hey Stephen> Thank you for the wonderful info! I appreciate the link you sent as well - answered many more questions. <Great> One final one that I can't seem to get a hold of, regarding power heads. I have an Emperor 280 filter currently on the 29gal. Is this enough for water circulation in a reef environment or should I consider a power head? I plan on taking the glass cover off (if you feel that's beneficial) and building a custom canopy as well. <You will most likely need more water flow, two opposing power heads create a amount of flow/turbulence.  Here is another good article on this topic: http://wetwebmedia.com/circmarart.htm Removing the glass will allow more light through, just be sure not to let the bulbs get wet.  Some egg crate on the top of the tank can prevent jumpers.> Other than that, I think I've got my equipment list ready, so it's time to whip out the wallet. (sigh) <I'd make a stocking list next, then the wallet.> Thank you in advance for your help. <No problem. -Gage> Stephen

- Water Circulation - <Hello, JasonC here...> Hi Guys how you guys doing I just finished reading the Daily Q&A and just can't stop laughing on one of the person putting milk into the fish tank and trying to taste it too that was funny never knew anyone who will try that. <Me either... I'm still disturbed.> But anyway my questions is has anyone tried the Tunze Turbelle Stream is it really that powerful as they claim of 3000+ gph and has anyone tried the eductors that is suppose to mix your regular pump 5x. <I've not seen eductors in the aquarium market yet, but it wouldn't surprise me. I have seen the Tunze Stream pump and was quite impressed with it's output - I would put my money into the Tunze, but from a cost standpoint might be better to try the eductor.> All I know is that one is 20x more expensive but not sure if both are the effectiveness in terms of water movement! <I'd say anything that improves water flow is a benefit, provided it doesn't slosh out of the tank.> Thanks in Advance! You guys have a good day! <You too... and keep the milk on your cereal! Cheers, J -- >

Getting Off To A Good Start (Pt. II) You mentioned powerheads for more circulation.  Why to I need extra circulation? <Circulation will perform several tasks in your tank. First, it provides extra movement that will keep detritus in suspension, where it can be picked up by your mechanical filtration. Also, it will help provide more even temperature and chemical parameters within the system, by "mixing" the water. If used with an aerating feature, you can also increase oxygen levels in the tank...Currents also help keep fishes active and strong...You'll see a definite increase in activity if strong currents are provided!> Also, about the live rock: How long should I keep the lights on if I use it? <I'd keep a "normal" day/night schedule...At least 8 hours of light would be fine...If you have photosynthetic life forms on the rock, they will benefit from the regular photoperiod> What does "cured" live rock mean? <"Cured" live rock simply means that many of the organisms that reside within the live rock, which often die during the shipping process, have decomposed completely, to the point where no ammonia is present in the water. Once this process is complete, the rock is considered "cured"> Do I wait until the tank is completely cycled to put it in?  And since it contains living things won't that contribute to added ammonia and nitrite levels? <Yes, the animals (living and dead) will contribute organics to the water. I prefer to cure live rock in a dedicated container, in which regular, massive water changes and detritus removal can easily be accomplished. When curing is completed, as evidenced by undetectable ammonia levels, and no stinky smell (trust me- curing live rock STINKS!) is evident, you can place it in your system. Remember, there are many different ways to cure live rock and cycle systems, so do a little reading on the WWM site, and use the technique that best suits you!> Thanks again, James <My pleasure, James! Good luck! Scott F>

A closed circuit and an open mind Hello, <Hi Jay, PF here tonight.> I have a 240 gallon tank that I will be setting up soon as a reef tank.  I have read in Anthony's circulation article I should have 10x + tank turns per hour.  I am looking at using the Dolphin Amp Master 3000 in a closed circulation loop.  This should give me 3000-3600gph.  My tank is glass that is not drilled.  The question I have is, what is the best way to plumb the intake to this pump so I will not puree all of my fish, coral, etc? Thank you, Jay <Ok, you can run the returns as spray bars, that would not push a huge amount of current in one direction. Another option is to use SCWDs (I use one on my sump return, and heartily endorse it). You can find them on the web at various prices. I would also read here, a nice plumbing site: http://website.lineone.net/~espsrg/diy_5.htm IMO, there is no one "best way", I would recommend reading some more on plumbing. A lot also has to do what kind of animals you want in your reef. SPS, LPS, and soft corals all have different current requirements. Some like laminar current (though many don't), some want a lot, others a little. Before anything else, plan out your livestock, otherwise you are putting the cart before the horse. Thing about that first, then plan on the current flow. Have a good evening, PF>

Too much water flow? <Hello again Luke, PF here with you tonight> I'm wondering... is it possible to have too fast water flow in the tank? I currently have 2x 150 power heads in 20gallon tank. The water is pretty agitated. <Well, you're turning over the tanks volume 15 times an hour, no surprise there> I have 2 small clownfish in there. Could the water current be too strong for the fish? I currently have no corals in the tank. <Well, unless the fish are being dashed about on the rocks, or are always struggling, I wouldn't worry to much. You can always swap them out for something with less power if you're really worried.> Thank you, Luke <You're welcome, have a good evening, PF> - Circulation Questions - hello bob, <Uhh... JasonC today...> great job I am on your site all the time. Here is my question. By the way Craig has heard it a million times and he is very helpful. Any how to clear things up, I have a 60 by 18 by 24 glass tank with an internal overflow with a 1.5 bulkhead drilled under the tank. It will flow to my 25 gal sump which houses a aqua-c Ev 180 skimmer pumped by a Sen 700g before going here it enter my 100 micro filter sock which then flows over activated carbon also in sump.  I have a single return drilled to the back of the tank with a 1.75 hole. I plan on having 1-1.25" pvc for that return which will include approx. 2-45 degree and 1- 90 degree elbow with a total of 5ft of linear pvc. Will an external Iwaki MD 70 RLT do the trick or a Iwaki 40 RXLT. <Both will 'work' - I'm sure you already know the 70 will have considerably more output.> I ordered a 40 but I think I went too small.  I want to go at least 10 times over. <The 40 RXLT at four head-feet can do roughly 1200 gph which would fit your bill.>  Attached you will see 2 flow charts, first the 40 then the 70....... can you help me ... this is killing me........... thanks Bob............... newbie <I think you already have the pump you need. Cheers, J -- >

- Circulation - <Hello, you got JasonC again...> Whoops....sorry, I'm on a Bloomberg and it doesn't keep a history like that. I was following up on a question I had re: a 180 gall used tank I'm considering. I was going to order a new one w/ overflow boxes built in, but this used one which is $1000 less is not drilled or anything. I was wondering exactly what the best way would be to get the water from the tank to the sump.  Jason said to get it drilled. <And I still say it...> I was just trying to get an idea of exactly what this method would entail and how effective if would be. <Any glass shop can do it for you.> I'm imagining something like 2 holes where PVC pipes would go up into the tank with straining caps on top. <Better to have multiple bulkheads on the back - there is much data on this in the FAQs, check here: http://www.wetwebmedia.com/plumbingmarart.htm http://www.wetwebmedia.com/circmarart.htm > These would in essence work as overflows right? <Yes.> Would 2 be enough? <More [bulkheads on the back] would be better, redundancy, increased circulation.> Thanks...Rick <Cheers, J -- >

Added circulation Hi All, I have a 75 gallon reef in which I have supplemented water movement with the addition of a single powerful PRO4 powerhead near the surface.  For the most part, I can tell I have enough current by the waving of my xenia, gorgonians and other soft corals.  However, near one side of my tank I have some button polyps that are barely swaying and particulate matter just seems to slowly float by in that area.  I even have some spots where debris likes to settle on the live rock and brown Cyanobacteria often grows on my cabbage coral and gorgonian. I tried moving the filter outputs around, but this compromised surface turbulence. Should I add more current?  I am concerned with the aesthetic implications of doing so, or adding too much current!  Should I have so much current that my polyps are vigorously swaying?  If they're not swaying should I be concerned?   <Sounds like you need more circulation and perhaps a look into improving nutrient export/maintenance. I would add the powerhead to pay particular attention to the low flow area. Gauge success in placement by the results from your inhabitants and whether the Cyano returns.> I know this maybe kind of a silly question, but I am on a quest to learn for optimal conditions in my reef and the last time I added a new power head, my mushrooms started flopping around and did not open up all the way.  Not to mention my gorgonian looked like it was in a hurricane storm. <The Gorgonian probably wasn't affected but the mushrooms did! Place the powerhead according to your inhabitants and their needs.> Thoughts as always much appreciated. Regards, Steve Bihari <Cheers, Craig>

- Water flow and circulation for 150G FO - Hi All, <And hello to you, JasonC here...> I am converting a 150G soft coral reef tank to 150G FOWLR tank. I have a lot of fish in there but I am in transition in finding new homes for the small reef fishes. Also adding the new ones as I go. I know that water flow should be high in reef tanks but how much should I keep in a fish -only system? <I'd keep things equally high...> Is there something like 5x or 10x like thing about fish-only systems. <10x is good to shoot for.> Here are my new fish that will reside in the tank: - Harlequin Tusk - Emperor Angel (Bad call on my part. Needs to go back to LFS) <Would be fine in a 150.> - Picasso Trigger - Pyramid Angel - Rabbitfish (double-black mark one) I have kept some mushrooms, toad stools and softies like colts to give a little better aquascape but please let me know if you think that some of these have no chance in there. <Nah... sounds like a good list to me.> Any suggestions on keeping some cleanup crew or inverts. <Get them in there first.> Shrimp are of course a snack for the tusk. <Eventually, yes...> Any alternatives? <To a cleaner shrimp? Neon gobies - likewise, get them in there first.> Have heard about UV sterilizers a lot. Do you think having a UV in there is something I should consider. <Sure, for about two minutes and then forget about it.> Regards, Razi Burney <Cheers, J -- >

FOWLR Circulation set-up Hello WWM Crew! I need some help for my 125-gallon (72"x18"x18") FOWLR potential set-up.  I have an acrylic tank with 1 corner overflow.  The overflow has a 1" bulkhead attached, with a hose going down to a wet/dry.  I havea Mag Drive 9.5 in the wet/dry as a return pump, which delivers 800 gph with a 4' head.  From some of your feedback to other aquarists, it sounds like that Iprobably could only get 300 gph through that overflow bulkhead.  So it appears that my return pump will be too much for one overflow to handle.  Am I correct in this conclusion?  What would happen with this scenario? <It will overflow onto your floor!  I wouldn't do that! A 1" drain will theoretically drain approx. 600 gph. so you need another drain/overflow, larger bulkhead drain in the current set-up, (provided the skimmer box could handle 600 gph), or a smaller pump w/valve (designed for something closer to 600 gph) to control flow rate.  This depends on fish load and if 600 gph is acceptable for filtration as overall circulation will be closed loop as below.  For figuring drains and skimmer box sizes Reef Central has a nifty drain calculator in the left menu bar, check it out if that's the way you choose to go.> And if my conclusion is correct, would you recommend adding another overflow (with a 1" bulkhead) to the other corner?  I've found a site where I can purchase a pre-fab 2-sided overflow.  Would you recommended this?  And how easy/difficult is it to install into my tank? <Not difficult, depending on how "handy" you are.  Or have an acrylic shop match the one you have and glue it in place. Either way, you need to either go lower flow for filtration or more drain.> I will then need to install another input bulkhead into my wet/dry (CPR CR1000--rated at 150g). Again, would there be any negative ramifications from this modification? <Not likely.> Furthermore, I am planning to drill holes and install bulkheads at the back of the aquarium to run a close-loop circulation system.  My plan is to install 3 1" bulkheads near the bottom of the tank: one on the left side, another in the middle, and then one on the right side.  The one in the middle will take the incoming water to a pump, maybe an Iwaki 40RXLT, and then from the pump to a PVC T that will distribute the water to the two side bulkheads.  What are your opinions about this plan?  Do I face any problems because all 3 bulkheads are to be installed near the bottom of the tank (i.e. water pressure too much)? <No particular problems with this at all. Do properly size pipe for both pump intake and manifold. Better to oversize one size to get full performance from pump. Use valves to control/adjust flow as needed.  Make sure the intake is properly shielded.> I appreciate your feedback.  Your site has been very helpful to me and other aquarists in this exciting hobby! Regards, Ed <Glad to hear it Ed! Have fun....and don't forget to QT fish first!  Craig>  

Moving Water... Sorry to bother you, but I am at the end of my rope. <Never a bother! Scott F. with you today!> I have a 135 gallon acrylic aquarium w/ a built-in pre-filter.  I ordered it from Tenecor (135 gal. flat back hexagon).  I have a problem that I cannot figure out. <Together, maybe we can> I keep getting these small bubbles out of my return lines.  I have eliminated the protein skimmer as the cause of this.  Here is what I think the problem is... <Okay...> My return pump is a Little Giant 4MDQX-SC1 pump.  It is rated at 1225 gph at 3'.  My return line is about 6' long.  I installed a ball valve to restrict the return flow, and it helps somewhat.  When I run the ball valve wide open, the sump drains faster than the pre-filter can fill it.  Plus, the bubbles only increase. <Sounds like a major cause, IMO...> I'm pretty sure my pump is too big for the job, but want to get a confirmation from you guys.  If my pump is indeed too big, what is the recommended size (in gph)?  Can you recommend a QUIET one? The one I have is pretty loud... <Well, "too big" is tough to determine, really...Yes, head is a big factor, but so is the number of returns and the amount of outlets, etc. The microbubbles might be caused by something as simple as a loose connector, a pinhole leak in a seal, etc> Also, how much (in gph) should I be re-circulating in the aquarium? <Another one of those questions with no absolute answer...Prevailing reefkeeping thought is that you should circulate the tank volume at least 10 times per hour. Hard-core SPS geeks and masochists like myself go for 20 turns an hour...In fact, I have friends who move 30-40 times tank volume per hour...Really depends on the needs of your animals and their requirements...do a little research on the animals that you intend to keep, and design the circulation accordingly> Thank you, Jeff Skaggs <No problem, Jeff! Good luck with this situation! Regards, Scott F>

Overflowing With Ideas! I just bought a new 180 gallon tank.  It's 60" long by 30" wide by 24" high. <Nice dimensions! I like wide and shallow tanks. Scott F. with you here today, admiring the dimensions of your tank> It's acrylic. I got a great deal on the tank, but it was already built so there is one modification I'd like, but I don't know if they are really worth bothering with.  There are two overflow "towers" in the rear corners of the tank.  Both of them are eight inches square.  I'd really like to have an overflow all the way across the back, connecting the overflow towers.  I don't want to take up eight inches all the way across the back.  I'd make it two or three inches from the back of the tank and probably about six inches deep.  Because the tank is acrylic, I don't think cutting the tower to fit the overflow would be difficult. <Should not be too difficult, if you're good at working with acrylic> But is it worth adding this to get more surface skimming or are the two eight inch towers sufficient? <Well, it sounds like they should do the job...Of additional importance is the width of the standpipes inside the overflows. I do like the idea that you're talking about with the full-length overflow...Anthony mentions an overflow concept such as this in his "Book of Coral Propagation". Do check it out! Regards, Scott F>

Closed Loop Flow rate I did go to RC and enter the params... all it said for a result was that I have 7 feet of head pressure.  They even broke it down to 6 feet from the 90-degree elbows and 1 foot of actual height.  But this would imply no flow for my system. <If you have flow, there must be one or more of several things happening: Actual head height is not as much as assumed, pump output is greater then assumed, less actual plumbing restriction than assumed.> Side question: I have the pump submerged in the tank about 1 foot below water level, then water goes out over the rim of the tank, down about 8" to accommodate the SQWD and then back up over the rim and into the tank.  Should I consider any head pressure from this arrangement from the 1 foot up (assuming the 8" up and down will cancel out) or does it just have to do with the water level in the tank (i.e. about 2" of head to get over the rim of the tank)? <Actual head height would be less than 10" as the 8" doesn't  "cancel out", but it isn't a straight 8" head either. Pump depth and only pushing 2" over rim also changes equation in pumps favor.> If I don't need to include this in the calculations then I come out at about 6 feet of head pressure, and the pump is rated around 320 g.p.h. at that point... that would explain it.  Although it seems like more flow than that... it's really hard to tell. Jeremy <There you go. Hard to judge from there without a flow meter.  Craig>

UV/Protein Skimmer Once Again I am calling on your wonderful help. <Welcome back!> We purchased a UV Sterilizer for our 75 gallon soon to be reef.  Would it be ok to have the water that comes out of our protein skimmer be the water that enters the UV Sterilizer?  Both machines have the same pump. Thanks Annette <Do you mean a direct connection?  As long as both the skimmer and UV unit receive the correct flow rate and there isn't a bubble/air trap (from bubbles in the skimmer effluent) there is no problem. You might tee both off of the same pump, separately.  Craig>

Deep sand bed and random, turbulent flow Hello to all, I just got my 55 gal corner bow drilled and a diy 20 gal sump built and am now waiting for my pump to come.  Its an Iwaki md30rlxt.  This should give me 960 gal per hour plus the 350 from my canister filter should give me around 20X turnover rate.  This should give me enough flow for the Deep sand bed and live rock, but I am still a little unsure of how to achieve the random turbulent flow that Anthony has mentioned in several of the faq's.  The canister filter takes water from the bottom of the tank and returns it sort of across the surface.  The drains for the sump take only water from the surface so I was thinking of directing the pump return from the back corner down towards the front bottom.  Do you think this will be sufficient, or should I try to make some sort of return manifold? >>Hello, Marina here.  To answer the question, yes, I feel you should devise a manifold.  You say you're going to set the spray bar so the outlet flows across the surface, this is good (surface agitation and all).  So, what you have left is the outlet from the sump back to the display (as I understand it).  A manifold can be devised simply enough with PVC fittings.  I use parts from an irrigation supply, other folks go to places specializing in marine aquatic supplies.  Check the site for sponsor's links, or do a quick Google search on the site.   >>What I would do is split this into at least two outlets, using a "Y" configuration would be best so you don't reduce flow rate too much.  This would be behind the tank.  I would plumb in gate valves on each "arm" of the "Y" so you can fine tune this flow.  Then, you can set it up so that one outlet returns at or close to the surface, while the other releases deeper into the tank.  All of this can be done before you place the aquascaping, in my opinion the easiest route. All the pictures of home made manifolds that I have seen look pretty complicated.   >>At first, maybe so, but they're basically like a switching station where the main flow is divided into channels.  You use gate valves to tune flow rates. Also, after I finish the setup I am going to seed the sand bed with a recharge or detritivore kit that I found at inland aquatics.  Are these worth the money?   >>I've never used one, but there are folks who feel that it's a help.  If you're going with good quality live rock, that ought to be enough to seed.  You'll have to allow cycling time no matter what, the degree to which this can speed up the process is variable. (Ok, gang.  I happen to know that Tom O'Toole is another Reefs.org Taskforce member, is there a problem with suggesting this guy talk to him?  Dissemination of information and all, and I've been cross-referencing both sites as much as possible.  Just let me know.  If yes, then please add: If you would like to speak with others who have used these kits, try http://www.reefs.org in the discussion forums. -->If not, then just leave it out, add comments if you feel it's necessary.) I have not found a single store in my area that has anything like it.  In fact none of them have sand in any of their tanks so I can't even hit them up for a cup o' sand as suggested in the faq's.  Last question is do I need to quarantine the recharge kit? >>No, if you decide to go this route, in my opinion it won't need to be q/t'd. Once again a great site Bryan and Dana Flanigan

Water flow and carbon use 3/11/03 Dear Anthony: Thanks for the prompt reply. <Always, welcome> The powerhead (211 GPH) is approx. 1.0' & at a 45 degree angle from the gorgonian. Water params: ------------- 0-5ppm NO3, 0-5ppm NO4, 0ppm NH4, 8.2 - 8.4 PH, 78-80 F TEMP., 4.0 meq ALK,1.025 SPG, 380ppm CA. NO ACTIVATED CARBON. WATER CHANGES: 15% WEEKLY. LIGHT: 2X 55W PC (1 x 10,000K actinic, 1 x 7700K white) <With only 15% water changes weekly, you really need to use carbon regularly to have any chance at maintaining water clarity for optimal light penetration. You might consider an additional power head to oppose the first one to create random turbulent water flow... laminar is harmful or at least not helpful to most corals. All else looks very fine to me :) Anthony >

Confirming flow rate Hey guys. I have a quick question. <Ok, then, one quick answer. Don> Is 20 times the water volume in a reef tank, really the correct flow rate? It just seems like a lot of water moving. So for a 100 gal. tank w/30 gal sump, I would need approx. 2000 gph water flow. <Depends on livestock. If you are going for high flow inhabitants, then yes upwards of 2000GPH would be recommended. Remember, this includes all water movement pumps, powerheads, skimmer output, etc.>                                         Thanks, Bill

Overflows and pump sizes Hi to all, I just got my 55 gal corner bow drilled for 2 - 1" bulkheads.  I am going to plumb down to the sump according to the directions and advice I have found on your faq's.  I think I can handle that. My question is about the return pump.  Dr. Foster's and Smith have GPH flow rates for 1" overflows at 600-800 Gph each. So, I am looking for a pump, but I don't know how much flow rate to shoot for.  Should I get a pump rated at more than I need and throttle it back or get one just at the rate I need.  I am looking at the Iwaki md 70RLT at 1500 gph at 4' <Hey Bryan!  Use the flow rate/head chart for Iwaki's to see what they actually deliver at the head height (surface of sump water to surface of main tank water) you have from your sump up to the main. I would also advise oversizing the overflow plumbing to allow you some wiggle room and a chance to reduce noise with less flow-air sucking/pulling. Also search on Durso-pipe drains, a good idea.> That's it for the actual advice needed. Do you know of any aquarium clubs around South New Jersey? <Look at the club forums at WetWebFotos or Reef Central, I'm sure there are several choices.> Also I read some faq's about possibly putting something on your website to reduce your backlog of stupid questions.  As a dedicated reader I say go ahead.  I can't get over the number of people who write in about questions that have been answered so many times already.  Some one suggested a page with links to the most popular questions like Ich.  I honestly would like to see something like that although if the daily's get too boring (I.e. the tongue lashings directed at those who buy fish uninformed and then look for advice are all weeded out)  you will lose one of the most enjoyable parts of the daily's IMO.  Anthony is my favorite. I got a good dressing down from him when I first started as an uniformed fish keeper and not only did I learn from it.   It got me motivated to actually do some work and research to make the lives of my charges better. <No stupid questions, just those we answered already! That's out Anthony!  Sometimes a good tongue lashing with a little humor doesn't hurt! We're glad he helped!> You guys are a shining beacon  (now that's just tooooo sappy) Bryan and Dana Flanigan <Thanks Bryan....Craig, the dim flashlight!>

Optimum flow rate What is the optimum flow rate that you should strive for in your tank?  I have a 190 gallon with fish and live rock.  I've heard it should be at least 5 times your total gallons but what is optimum?  Can you have too much?  I'm going to be running a Mag 12 on mine. . . . at 5ft. it does about 1150 gph.  This ok? Thanks. <Hi Elizabeth. This depends on the type of fish you keep. Some fish naturally dwell in still water with slight current and others like some of the Tangs, etc. live in surging outer reef and more open strong flowing water. Anywhere from five times to twenty times turnover depending on inhabitants. Yes, you could have too much but not with 1150 gph in a 190. You could do 1900 gph and be in the ballpark.  Look up the current needs of your fish at WetWebMedia.com  Craig>

Re: Optimum flow rate Yes, I do have fish that love strong current. . . a Naso Tang, yellow tangs, large wrasse, and maroon clown.  If I decided to go with a Mag 24 which at 5ft. would give me 1800gph what would the benefits be other than the fish being happier?  Thanks for your help!  P.S.  If I ever decided to go "reef" would a Mag 24 be too strong? <Fewer dead spots, better overall circulation, less tendency for algae problems, etc. For an LPS/SPS up to 20 times turnover would be suitable, so no, it wouldn't be too strong depending on the corals you want to keep, in fact, a bit underpowered unless it's a soft coral reef.  Do look at some of the external pumps (Iwaki, etc) for output and energy use.  Craig>

Re: Pumps-Let it flow!!! Craig, Appreciate you guys so much. I am running two Iwaki 40 pumps.  They have 3/4'' inlets and 3/4'' outlets.  With my Durso stand pipes screwed in to the bulk head actual size is 7/8 '' opening for the water to flow through.  Should I go for the 1'' after leaving the pumps?   Thanks guy!!!!!!!!!!!    Charlie <Hey Charlie, let's get on the same page! The pumps pump water up to the main tank in what is known as return lines. With two Iwasakis with 3/4" inlets and outlets, just run 3/4" lines as returns to the tank and the inlet of the pump.   Separate from the pump system, the water drains from the tank through overflows, sometimes fitted with Durso pipe drains with vents to reduce noise and increase flow of the passive drains. These have nothing at all to do with the size of the pump return lines nor are they attached in any way. One is a drain and the other a pumped line that pumps the water up to the tank.  The only relation between the two is that the drains must be big enough to passively drain whatever water the pumps pump up to the tank. So, the Durso pipes are the drain into the sump, and are not connected to the pump. The pump will work fine with3/4" pipe. You could use 1" if you have to pump up any distance, but any further reductions after that will reduce any advantage to larger pipe. IOW, running 1" pipe up to a 3/4" fitting will only deliver the flow of 3/4" pipe. If however, you have 1" running to two 1/2" or 3/4" outlets, the 1" may help deliver the most from the pumps with the least work. I hope this helps!  You know where I am if not!  Craig>  

Re: Pumps-Let it flow!!!                   Anthony------- <Hi Charles, Anthony is taking a well deserved break from WWMail for a bit, he will be back in a week or so...   Craig here for this long awaited answer!> I have a 135 gal. tank. I was going to use two 40 Iwasakis. 3/4'' outlet on both. Would using a 70 with a 1'' out let be any better? <You have a couple of considerations here. The 40's put out 750 gph and the 70 puts out 1500 gph. so the gph is a wash. Having two pumps adds redundancy for at least half flow in the event of a pump failure, but cost twice as much, may use more power. I would likely use the 70, if it is correctly rated for your use, and use at least one size larger pipe size or the Iwaki suggested size.>   I thought the flow from the two 40,would give me more then the one 70 is this right? <Nope, the same.> One more question, I read today that on your return pump, if you have to go any higher than 2 or 3 feet head ,that you should come out about 9''from your pump, then go to next larger pipe size, to cut down on friction. <I like the larger pipe size, right out of the pump outlet.  The 9" isn't necessary, most return pumps are vertical outlet so I go bigger right out of the pump.>     If so, would you take this next size bigger all the way up to the bulk head? <If your returns are through bulkheads, yes. These should be above the water line to reduce risk of siphon in a power outage.> Thanks, enjoying your book   Charlie <Have fun!  Craig>

Water flow and overflows Hello and thanks in advance for any advice you might offer. I am recycling an old 75 gal. aquarium into a tank meant to house some live rock, soft corals and a light fish load. <Sounds Good> I have purchased a remora skimmer, built a hood housing 4 55w PC florescent bulbs and what I think is everything else I will need ( i.e. heaters, test kits, salt, supplements). I have an old 20 gallon aquarium I have also recycled as the sump for the 75 gallon. I have purchased a Mag 12 pump for use as a submersible for my return and am constructing the return so that the run from the pump to the "tee" on the tank is 1.5", 1" around the loop at the top of the tank and ending with 3/4" spouts at six points around the tank (btw...is standard PVC glue ok for this application?). <Yes you should use the pvc cleaner, primer and glue on all connections. Unless you are using thin wall pvc then you should omit the primer as per instructions> The head from the pump to the top of the tank is 4' plus whatever the tee and 3 90 degree elbows and the spouts add to back pressure. I am doing this to eliminate the need for power heads (I hope). <An excellent idea> My first question is will a Mag 12 provide enough circulation for what I plan to keep? Second, will I need power heads? And third, I will be using a CPR overflow since my tank is not drilled ( I don't really want to go there), how much capacity does the overflow need to have to accommodate the needs of the return pump? <The Mag 12 is rated at 1130GPH @ 4' head. But, alas, each elbow is +1' and each tee is +1.5' and each 6' horizontal run is 1'. With this new info, you head pressure is something like 9-10' and the Mag 12 is around 600GPH. You add the flow from the skimmer pump and you are probably around 800-900GPH, am I close? This would give you around 10x turnover which would be sufficient for low flow species. You may need to add some 'spot' flow to certain dead areas so maybe you could hide small powerheads in/around the rock. The manufacturer of the overflow will have a GPH rating and you should match the above. I would over design by as much as 20-30% to give yourself some elbow room on the overflow.> I hope this all makes sense. <And I hope you can make sense of the reply. Take care, Don> Thanks again.

Circulation Question Happy Presidents Day . I really enjoy this web site , thanks a lot. I have a question about circulation . I have a 180 gal oceanic with the center glass brace .The pump is a Iwaki  md-100rlt so the amount is not a problem, I have ball valves regulating the volume. On top of the center glass brace I have 2 sea swirls (90 deg. rotating dev.) At present they are set to rotate ,the one on the right, center position to the right side then back to center. The left side, center to the left then back to center. I hope that wasn't to confusing. What would be your advice? I was reading some of the articles on the web site but didn't see anything about rotating devices. Thanks a lot. Robert McNinch <Think of the SeaSwirls as circulating fans......when you use a circulating fan you want it to move the air around you to make you comfortable. Sometimes you have to adjust it to work where you are. The same is true for the SeaSwirls, they need to be adjusted to provide circulation to specific areas and creatures, there is no standard position that does this for all set-ups. (no tank is the same). Set them to provide the correct circulation for your inhabitants. Craig>

- Symbiotic Gobies and Circulation - Hi Crew!! <Hello, JasonC here...> First off, I have been reading TONS on your site and have learned an incredible amount.  I read something today that has me concerned, regarding water flow and soft corals.  I have a small (2-3") brown star polyp colony in my tank.  The water motion in their present location is mostly in one direction.  I can put them almost anywhere in my tank, which would mean potentially less flow but a more changing direction.  I have had this colony about 4 weeks, and they are doing great, even seem to be growing nicely. Do I fix it if it's not broken (move them)? <I would... do consider perhaps another power head in the tank to help stir things up some more - variation in flow is very important for long term success.> My next question has to do with a Pistol Shrimp - Goby tank I am considering for the office. What is the ideal substrate for burrowing? <Sand.> Best (most likely to bond) Goby? <Chances of getting a non-paired set to "bond" is lower than winning a high-stakes lottery. Unless you obtain both as an existing pair, it's not going to happen. Alpheids are incredibly diverse, and the pairing between the goby and a particular shrimp is very specific. You can't put a random goby and random shrimp together and expect them to get together... unless you get them as a pair via expert collection, even then one or the other probably wouldn't make the trip... it's just not easily feasible.> Because they are both low in the tank suggestions for other occupants? <Based on the size you mention... I wouldn't put anything else in this tank.> What is the best clean up crew for this tank, I know pistol shrimp are formidable hunters? <You would be the best clean-up crew.> Any other sound advice for this concept? <Learn to dive and go see them where they live... not to be crass, but it's just not realistic in a captive system.> BTW, this tank will be a smaller, probably ~20g, and dedicated to this idea. Thanks again for offering such sound info time after time, Bill <Cheers, J -- >

Cyanobacteria/BGA and circulation - 2/14/03 To whom it may concern  :o) I've read the posts about controlling BGA by eliminating dead spots and improving circulation in your tank, so I tried a little experiment:  I had one silk plant (deco) in my tank with some Cyano on some of it's upper leaves - about the only presence of BGA in my tank. Anyway, I aimed a powerhead right at it and blasted it until the flow forced it to bend double and almost touch the substrate - kinda like it was caught up in a tornado - anyway after a week of this, guess what?  The Cyano actually increased!! What gives?? <DOC levels, phosphate and nitrate levels, lack of water changes (large enough), allowing thawed pack juices from frozen foods into the aquarium, lack of adequate chemical filtration (weekly/monthly carbon), weak skimmate (light color or volume).... Nutrient control overall, aging fluorescent lights... all valid catalysts> Xeo <Anthony>

7 Circulation Questions What's up crew!   <Takin' a break from fraggin' to answer some mail!> Just had a couple of issues that I know you guys can answer, as always.  First I'll give my rundown.  75 gallon reef, 560 watts of VHO w/ icecap, emperor 400 w/ gorgeous bio-wheels, 150 gallon rated wet/dry filter with built in protein skimmer, 10 gallon refugium.   Issue one, circulation.  I have my return pump w/ a hose that connects to a "thing" I made.  It's a "T" made from PVC that allows water to be returned on each side of the tank, a total of about 500-600 gph.  Then I have two power heads on each side wall of the tank at about 200 gph each.  Then the current produced from the Emperor 400.  Do you think that is enough.  If not, how much more? <This depends on what you want to keep, with softies usually preferring lower flow than LPSs, sps corals. The desired range is 10-20 times total tank volume turnover, or in your case, from 750 to 1500 gph.> Issue two, yellow leather.  I purchased a yellow leather that has yet to stand up (about a month old).  I have moved it around a few times and still nothing.  It opens up and looks great (still not standing) in the morning before the lights come on but looks like crap when they come on.  During the day some of it is brown, some is dark yellow, and some of it looks fine.  Where should I position it and should I direct a small power-head directly on it. <A Fiji Yellow Leather? These like high light, preferably metal halide, or placed high up in your VHO tank. They tend to be more brown/less yellow under lighting other than MH.  Moderate current, enough to give it *very* slight movement. Sensitivity may be to another tank mate.> Issue three, and final, water parameters.  For months I tested the usual salinity, pH (8.6), ammonia (0), nitrites(0), and nitrates (0) which I'm proud of.  Recently I began testing calcium and noticed that it never got higher than 350, so I have started dosing Kalkwasser.  What else should I be testing for? <Alkalinity(3.5 - 5 meq/l), magnesium with Kalk use (3 times calcium).> Oh, and I evaporate about one gallon per day.  Any ideas on this? <Not really a problem. This is enough to dose calc in a drip overnight.>   Thanks guys for all your help.  If you had a cable show, I'd watch it. <A new Sunday AM "gardening" show! Sure hope this helps you out! Craig>

5 gallon circulation alternatives Which of the four alternatives do you like best? Any other alternatives? Sump flow rate goal? <Not an issue.> Total flow rate goal? <This is the requirement that is important, as it is in the main tank we need the circulation/water movement.> I am setting up a 75 gallon AGA reef ready with 30 gal sump, TurboFlotor 1000. <Cool! Not our fave skimmer, but acceptable. Look at Euro-reef and Aqua-C, much more efficient.> The overflow is good for 600gph or less I believe. I am trying to find the best alternative to increase total circulation to acceptable level for mixed reef tank. With 4x96w PC SPS or clams are unlikely. I have purchased an Iwaki MD30RLT (510 gph) not the higher flow RXLT (ok, so my first mistake). I plan on trying one of the new Squid wave makers, may be my second mistake. <You need at least 750 gph up to 1500 depending on inhabitants. Plan on more and turn it down if needed, use pump flow charts and factor in a healthy pump size increase to get the desired flow. Also use larger pipe throughout, you won't be disappointed.> - Alt1 Use one predrilled hole for return line and the larger one for drain to sump and add powerheads in tank. Looks bad, failure issues, heat, looks bad. <Yep, looks bad, works bad.> - Alt 2 Drill additional return holes in side for closed loop systems. Tank is in basement already so trip back to the glass shop (if I can find one) not appealing. <Or in bottom. Depends on if glass is tempered on the sides or not. Sandblasting works. A good choice with obvious considerations for you as stated. Best for desired flow, depending on flow rate allowed in option 4.> - Alt 3 Amiracle or DIY hang on to feed the closed loop system. Of course I got a reef ready so I did not have to use a hang-on. <Un-reliable in power outages, require powerheads to resolve siphon loss when power comes on. You have better options.> - Alt 4 Use both predrilled holes as outlets and plumb returns over the top. Might still not be enough flow and I am not sure how the overflow would react to a larger flood over the top. <A good option depending on flow rate. You don't give me the pipe size for these, so go to one of the WetWebMedia.com sponsors like Foster and Smith, and look at add-on overflow boxes and the passive flow rate they get from various size plumbing. Yours will do the same, but be conservative and assume the flow will be a hair less.  Add both flow rates together (for both pipes as drains) to see if it approaches what you need (anywhere from 1000-1500 GPH combined would be great). I think the overflow will handle it fine, do check out Durso set-ups and venting to increase flow and reduce noise. Plumbing the returns with a manifold and inlets over the top is not difficult and can be kept out of sight. Again, go much larger on plumbing then you think you need. Some pumps with 1" outlets only get full flow delivery with up to 2" pipe. Plan accordingly and use valves to reduce flow if needed.  Have fun with your new system!  Craig>

Fluval/refugium idea hello to all! I am currently running a Fluval 404 on my 65gal tank.  It sits directly behind the tank/not in the cabinet.  By your FAQs and helpful emails I am deciding on a refugium for my tank.  I have found some nice DIY plans online that I plan to follow.  My plans are as follows: 20gal tank for refugium, I would have the Fluval operating as normal but using the output of the Fluval as the input to the refugium and then using a MagDrive 5 to pump the water from the refugium to the tank. <Uhh, don't do this. There's no way to balance the rate of flow between the tank and refugium... Either drilling the tank or using some sort of overflow box (on the main tank or if the sump/refugium can be placed above it, on this container)... Float switches are not an answer here either> My reason for the Fluval is I don't want to waste having the filter and I don't want to use a siphon box.  Would this configuration work?  I have read over relating FAQs and haven't really found any information regarding something like this. <No> Also for quick question, I have seen these in-tank egg crate refugiums, do these really work? <Yes, can. Bob Fenner> Thanks, Jason-Surfs up!

Pumps Dear Crew: Bob's answer to one of today's (2/8/03) FAQs raises another question for me because I have been contemplating a similar set-up. To quote: "My plans are as follows: 20gal tank for refugium, I would have the Fluval operating as normal but using the output of the Fluval as the input to the refugium and then using a MagDrive 5 to pump the water from the refugium to the tank. <Uhh, don't do this. There's no way to balance the rate of flow between the tank and refugium... Either drilling the tank or using some sort of overflow box (on the main tank or if the sump/refugium can be placed above it, on this container)... Float switches are not an answer here either>" The Question: Can't the input and output to the sump/refugium be balanced by using the same brand/model pump on each end? <Mmm, no... impossible to match... flow rates vary on basis of change in cleanliness of filter media, variances in water level...> I have 2 Fluval 404s which have flow rate adjusters on the connectors. I was considering using the first to pump water out of the main tank down to a sump refugium and then having the second pump water back up to the tank, balancing the flow using the rate controls on the Fluvals). I thought this would prevent flooding after power outages because both pumps would come back on without worrying about broken siphon. Do you think this is a bad idea? <An exceedingly poor one... if you'd like, try this out (WHILE YOU'RE THERE) for a few minutes to an hour or so... You'll see. Bob Fenner> Thanks, Steve Allen Re: Pumps No need to test. I'll take your word for it! Thanks. <Okay... but next time you want to wash the floor, let 'er rip! Bob Fenner>

Water Turnover Hello all, wow it seems like you guys are getting more and more questions every day!!! My question is about water turnover. I read that water turnover for a reef tank should be between 15-20x. I just wanted to be clear that what is meant by turnover can include powerheads so if I am running 2 powerheads, 1 @ 175gph 1 300gph and a protein skimmer that has a powerhead that runs @ 295 gph for a total of 770 gph in a 46 gallon tank I would satisfy that requirement. I just wasn't clear that what is meant by "turnover" only meant a sump system where the water was leaving the tank and returning. <Cumulative, all movement in the tank, so your figures are correct. Although, you may have to add movement to a 'spot' to help with algae/detritus control, Don> Thank You. Angelo

Filtration and flow I set up my salt water tank about 2 months ago and its specs are: 75 gallon tank with about 100 lbs live rock and a few pieces of soft coral and at the this time no fish.  I have a power head and a red sea prism deluxe protein skimmer.  That is all.  My fish guy says that is all the filtration I need but I am not so sure.  He swears by the red sea skimmer.  Is that a good set up or do I need a different skimmer or additional hardware? <the skimmer should produce a cup of dark smelly gunk every day or two. If not, it may need to be adjusted, see the manual. If you decide that the Red Sea isn't for your tank, then see here for more comments http://www.wetwebmedia.com/bestskmrSelfaqs.htm. You don't mention what the sand bed is like? Nor do you mention the gph rating of the powerhead. I would think the rock and a skimmer producing good quantity of good skimmate, should be OK. Water flow depends on what species you decide to keep. Some are low, some moderate, and some high flow. I would suggest 10x to 20x turn over. For your tank 750gph to 1500gph. You certainly want a plan and this would call for more research. Don> Brett A. Podolsky

Powerheads Hi I would like to know how many powerheads I need to put in my 90g. that I am turning in a reef tank? Is the Power Sweep 228 a good product to use? Or do you have a better powerhead that I can use.                                    Thank You <Please see here re Powerhead number, placement and suggested models: http://www.wetwebmedia.com/powerhdfaqs.htm and the linked FAQs file above (in blue) on circulation. Bob Fenner>

Water flow Hey guys! First I would like to say what a great site you have and that it has helped me tremendously with my tank! <thanks kindly, my friend> The question I have is about my water flow, I have a 90 gallon tank with a sump that produces about 300gph, I have two power sweep powerheads, one on each side of the tank that are 160gph, I also have on the back of the tank an emperor power filter that is 280gph that I just added to give more flow and to help can keep the water clean. <hmmm... this totals around 1200 at best and somewhat diffusive at that. Modern reef aquarium need around 20x tank turnover to keep detritus in suspension. You really need another 600-1000GPH to get into the ballpark> A couple days after I added the power filter, my brain coral (Lobophyllia) doesn't seem to be as "meaty" the past couple days. <if even related at all, it is simply adaptation. No harm unless you blast flow directly on it (laminar is bad for almost any coral except sea fans)> I have it located on the live rock toward the top of the tank, and it is about 6-12 inches away from the powerheads and off to the side of the power filter. <Doh!> I am wondering if it is getting too much water flow? <not too much... just the wrong kind (laminar). Do read through the WWM archives (click new on WWM link on dailies page or find in the archives/root web) my article on water flow> I also have a candy cane coral which is looking great and doesn't seem to have changed with the increased flow. Both corals have been in the tank about 2 months Tank Specs: ph 8.1 alk 3.0meq <pH and Alk are both a whisker low> ammonia 0 nitrite 0 nitrate 1-2 calcium 400mg my lighting is 3 65 watt PC 8800k & 3 65 watt PC Actinic Aqua Clear Protein Skimmer temp 80 110lbs live rock <all else fine as per above> Second question is when I setup my tank I used dolomite for substrate as advised by LFS (I hadn't found your site yet), and I have been noticing that my alk has been constantly dropping to 2-2.5 meq, so I have been having to add Reef Builder 2-3 times per week to keep it up to 3-3.25. <very fine> I would like to change my substrate to either Arag-Alive special grade, <waste of money> CaribSea Aragamax, or Fiji Live sand. I'm pretty sure that any of them will help buffer the water but what grade of sand is better ? <aragonite is all the same and so-called biologically enhanced products have nothing that you cannot get comparably or better with dry sand after 2 weeks in the tank. Pick the cheapest fine oolitic sand that attracts you> I have read that many prefer fine sand(.5-1mm) to more coarse (2-4mm). <better for NNR and safer to prevent detritus accumulation> How can I make the transition from my current substrate to the new one as less stressful as possible to the tank inhabitants?? Soak the sand in advance to reduce cloudiness... drain and refill the tank quickly during the switch with a sump pump (fast) and cheap garbage cans to hold the water>   Thank you for your help!! Derrick <best regards, Anthony>

- Circulation Issues - Hello Crew! <Hello, JasonC here...> If it's Mr Fenner...just want to thank you for writing such a great book...on my second copy as the first looks like the Dead Sea scrolls from use! Well. another stupid question from me....I'm setting up my 125g FOWLR.  Have the sand ready, 120 lbs live rock ordered, skimmer and return pumps in place etc..  I'm using an AGA tank with overflows.  However, it looks like in order to achieve a 4-6 inch sand base, the bottom vents into the overflow will be covered by sand which presumably will end up in the overflow tower. Will this present an unforeseen problem for me or will it become an accidental refugium? <No it should be fine - the same thing happened to me.>  Dumb, I know, but I'd rather be embarrassed than sorry. <Not a dumb question at all.> Thanks for your advice! With humility, Michael <Cheers, J -- >

Re: Canister filter (water flow) Hello, I have a 54 gal. corner tank which I bought with an under gravel filter.  I just bought and installed a Fluval 304 canister filter as well.  My question is regarding the current the new filter creates.  How much is O.K.?  I have the filter valve partially closed to slow it down a little for now.  When the valve is open all the way the current is pretty strong in my tank.  Any advise would be appreciated. Thanks, Kurt Will   <Please see here: http://www.wetwebmedia.com/circmarart.htm the same principles apply to freshwater circulation considerations. Bob Fenner>

Water Flow how much is enough Over the years I have heard of more and more water flow in reef tanks. First it was five times the total volume in your tank than ten times I used ten times in my reef tank also I  try it in the discus tank and the fish love it. If you due your plumbing right you can good flow with blowing every thing all over the tank. High water flow if you do it right will not hurt the fish or the marine invertebrates. But how much is enough Anthony Calfo has said twenty times the total volume in your tank or more. In my own 180 gal reef tank I move 2700 gal per hour or fifteen times the total volume and if you look at the water it is hard to tell that you are moving that much. How much is enough, twenty times or more. In a year or more twenty times may not much water flow at all. Thank you Bob Anthony and the rest for getting all of us to move more water in are reef tanks and they are better for it        RGibson <Diving, snorkeling underwater most anywhere in the world's seas you can appreciate just how much water movement there is... there are very few places where "all the water" isn't moved past a given point every few seconds... Other than knocking organisms and non-living components over you can't practically over-circulate your water. Bob Fenner>

Water Flow Hello there, I have read hundreds of links on WetWebMedia, and I love the content/help it provides me.  Thanks. <Thanks for finding and saying so, my friend!> I have one question regarding your article "Water Flow: How much is enough?" I have often read the figure of 5-10 times total tank volume.   <yes... a common "rule" recited since saltwater keeping in the 70's (!). Modern reefing needs are more like 20X > Knowing that here is hardly such a thing as too much circulation, I have always opted  for large return pumps.   <Yes... correct. rarely is a tanks flow too much, more often just misapplied (as with severe laminar flow)> However, I am moving on to  a larger system, and I am revisiting all these issues again. My question is this: Does the 10 times total tank volume figure include the water turnover of all powerheads and the sump's return pump, or does it just mean the total amount of water that goes through your sump in one hour? <It can include all water moving drives... power heads at zero head in the tank (few if any needed hopefully) as well as the actual water flow delivered at head from the return pump> Thanks for your input. -Michael <my pleasure... best regards, Anthony> Refugium flow rate Dear Mr. Fenner: I'll pose this question to you, seeing as how I believe you are knowledgeable of the EcoSystem type refugium setup. I have a 55 gallon reef aquarium with an ALL-GLASS overflow, Durso stand pipe leading into two wet dry's beneath the aquarium.  The return is powered by a Mag Drive 500 from the sump back into the aquarium. I have a variety of power heads situated within the tank for circulation. I also constructed a 10 gallon refugium, in the ecosystem design...very similar with baffles and about 3 inches of Miracle Mud Substrate. I've read over and over again how a refugium's water flow should be no more than 3-5x it's capacity per hour.  Is this correct?  So I should be pushing for about 40-50 gallons of flow thru the refugium per hour?? <In general, yes> I'm a bit confused on this issue, and currently have a Maxi Jet 1000 powerhead supplying water to the refugium (which is located about 1 1/2 - 2 feet above the sump in a separate cabinet to the right of the tank.....and is gravity fed back to the sump). If I am correct that I'll only need to pump 40-50 gallons per hour thru the refugium, then can you please explain the following statement by Leng Sy over at Ecosystems: "What struck me right from the start is that when I asked Mr. Leng Sy how much circulation was needed through these system, his answer was a lot. In fact in a 120 gallon system that he has set up, he flows about 1000 gallons per hour through the sump. The sump is the area where the apparently very beneficial filtration occurs. Judging from the results that can be seen on the web site, the filtration is working extremely well indeed, especially since NO skimmer is used. You read that correctly: no skimmer is necessary on this system". http://www.fishdomain.com/article_miraclemud.shtml <Their experience varies from mine. Leng and I have talked over many issues over many hours (we're good friends, and go on dive/photograph vacations together), including this one (rates of turnover in algal/mud filters). There are practical limits and considerations... such as "blowing over" living and non-living elements in the filter, potential trouble with circulation gear, failure... You won't "get" much more from the utilization of these refugiums by circulating them anymore than 3,4 times per hour... Now, if you are looking for just the benefits of the circulation itself (aeration, current, moving sediment about...) more flow (whether it's through the refugium or not may be a good idea. However, you will not get more nutrient uptake, micro-crustacean and worm production, growth of macro-algae... by running more water through the living sump> Thank you for all the help you and your crew have provided me with these past several weeks. Regards, Steve <Thank you for your participation. Bob Fenner>

- Plumbing and Circulation - <Greetings, JasonC here...> Attached is a rather silly bitmap (Paint sucks) depicting my plans for a closed loop circulation system for a 75 gallon reef tank I'm planning. <Ahh yes, I got the image this time.> The pump will be an Iwaki WMD40RXLT rated at 1200 gph at 4' of head.  I should get a few more gph since I'll be using it at about 2.5 ' of head.  But with all the plumbing..... The PVC all around will be 1", modified at the tees to 0.75" to accommodate the flares and SCWD's. The outlets will be setup at different angles. <I think I get the picture...> "The SCWD (pronounced "squid") is a revolutionary device designed to provide alternating currents without the use of electricity. The SCWD mounts inline with 3/4" tubing, the two ports alternate the output, the bottom port is the input. A great alternative to expensive electronic ball valves. The SCWD will run on any pump with a minimum output of 50 GPH and a maximum output of 1400. The switching speed and current duration is dependent on the volume of water flowing through the SCWD. We have tested the SCWD with a mag 7 (700) gph and the port rotation was every 10 seconds. You can control the duration by controlling the flow going through the SCWD. "  From Champion Lighting (page down on their home page and there they are.) <Yup, I just went and checked it out.> What are your thoughts on this arrangement? <I think it will most certainly 'work' - how well is hard to say, but I think it's a good plan.> Also, will 2 SCWD's be sufficient (at ~$50 each) to randomize/break up the flow? <If they work as advertised and don't break too often, I'm sure they will do fine.> Thanks for your input, you guys are great! Mike <Cheers, J -- >

OVERFLOW & SUMPS Good day: Now that I have read all about the perils of siphon overflows, I want to get a tank with an built-in overflow.  However, now I am reading that a pre-drilled 55 gallon All-Glass, for example, has 1 overflow, which is rated at 600GPH, but actually flows only 300GPH in reality?!?  WHAT IS WITH OUR $%#%$# SOCIETY THAT EVERYTHING WITH A RATING IS ALWAYS OVERRATED?!?  WHERE ARE THE CONSUMER WATCHDOGS?!?  Ahem, sorry.  Okay, so I only have a FOWLR at the moment, but I want a tank that can handle the future possibility of a reef.  Your site says 20X flow for corals is good, right? <The more the merrier generally>   What about just FOWLR?  Will the 300gph (5.45X) be enough? <Likely so, yes> If I have to drill, I can't on the bottom because of the tempered glass.  But I don't want the back drilled, because I need to have the tank against the wall for lack of space. Can I special order 2 overflows from the All-Glass (or other) factory? <Contact them and ask.>   Do I want a tank without a tempered bottom? <... not really>   It does not sound like a good idea. And what's with sumps "rated" for a certain flow?  I am going to take a wild guess and say that they are overrated flow-wise too, right? <I suspect these ratings are "generalizations" as the physical restriction (for transit volume... the amount of water pumped up to the main/display tank) will be a matter of how fast the pump is able to pile water up above... in the surface area, drain configuration of the system>   Why can't they handle as much as you push through? <Think about this... the water accumulates "on top" of the tank being pumped to... if/when the pump/s go off... that water will flow back down to the sump/s... It's a good idea to have as long, wide of sumps as possible, and to "practice" with filling all with the pumps turned off, turn them on, and mark the lowest level of the sumps achieved, mark this on the sump/s and never fill them more than this... to provide for the inevitable power, pump failure. Bob Fenner>   anyway, thanks for being there!  Rich.

New System Setup Thank you Scott!  So far so good!  I have the sump setup and new Aqua-C Urchin Pro working. <Great! Glad to hear it. That Urchin is one cool skimmer, huh?> Two more quick questions please.  The siphon U-tube is a bit to large to allow me to close the tank lid as it sticks out to far from the back of the tank wall.  Must the Siphon tube be ridged, or can a flexible piece of 5/8" tubing be used? <Well, rigid siphon tubes can be problematic at times...I couldn't imagine the potential problems that could arise with a flexible one...I'd keep the rigid one and cut out (or have a pro do it) a section of the lid. Of course, the ultimate solution would be a drilled internal overflow...but that entails starting over again..> Also, since I replaced the power head in the tank with the outflow from the sump (Mag 5 pump at 4' below output should be 300+ gallons per hour), will  the outflow provide enough current in my tank?  It is a 37 gallon oceanic show tank. Thanks again! Bryan <Well, Bryan, depending upon the types of animals you are keeping, 8-10 turnovers per hour is not too bad. You can always add more circulation if you feel that it is needed, of course. I think that, if you could swing it- a more powerful pump would be a bit better. Or, perhaps you could construct a "closed lop" for extra circulation...Lots of possibilities if you're a bit crazy and creative! Good luck, and have fun! Regards, Scott F>

- Circulation & Pump Selection - Jason, Thanks for answering my questions so fast. <My pleasure.> Just one or two more and I can get this show on the road. My over flow is 1,200 gph, I would like to turn over my tank volume 10 times. Its a 135 gallon tank. That comes out to 1,350 gallon. <Missing the mark by 150 GPH isn't going to be noticeable, but you can make up for it with powerheads in the tank.> I have about 5' of head. Would two Eheim 1060 -602 gallon pumps be enough pumping power, or should I go for a little more pump. <I'm not familiar enough with those pumps to say definitively... please use the manufacturer's rating for the pump output at five head feet and do the math... that where the answer will come from.> If so does Eheim make a bigger pump? <I think they do, yes.> I cant find any listed. One more question, Do you think my 30 gallon sump is big enough?. <Should be, but larger would not hurt.> Thank you so much Jason. Charlie newbie <Cheers, J -- >

- Circulation - Greetings Crew, <And JasonC again, at your service.> Another quick question from a numbskull (and thanks again for your previous answers to my queries...mostly JasonC at this point!) This one has to do with circulation.  Setting up a 125g FOWLR using a DSB (appx 5").  Will be using a Euroreef CS8-1 skimmer powered with a Sedra 5000 pump (500gph) in a 30g sump.  I'm also going to use an Eheim 2250 canister filter for some added filtration, but mostly circulation.  The Eheim is rated at 265gph turnover.  If, as you folks suggest, I should be turning my water over 10 times (1250gph) then with the Eheim attached should I buy a pump for the sump rated at approx. 1000gph?? <You could, it wouldn't hurt.> Or need I also consider the skimmer pump's role, if any in all this, too? <The skimmer doesn't factor into system circulation at all.> Would throwing another Sedra 500 in the sump be sufficient for returning the water? <Not familiar with the Sedra's performance as a return pump, but there are other options.> I will also be putting 2 or 3 Maxijet 1200s in the tank as well. <And those also add to the 'total' amount of water circulating in your tank.> So sorry to offer up such a seemingly silly and convoluted question and throwing all this math at you so early in the morning, but please consider the source. <No worries.> Again, many thanks! With great humility. Mike      <Cheers, J -- >

- RO & Circulation Questions - Jason, <Good n'you?> Thank you very much for your response. <My pleasure.> It helped greatly. <Even better!> As it turns out, I found that the HD/Lowe's RO units are more costly than ones I can order on line from aquarium supply stores (I think due to the mandatory storage tanks and fancy chrome faucets that come with them).  As a result, I will wind up getting a 25 G model that should easily allow me to follow your advice on filling the new tank over a few days. I hate to be a pest, but I have 1 additional question (for now ;-)).  I just read Anthony's article "water flow, how much is enough", and what I'm unclear on, is when he says that most keepers of corals advocate 10-20 times the tank volume per hour, is this the total between everything including power heads? <Yes.> Or does that 10-20 spec just take the main system pump into account? <Total system circulation, including powerheads.> Thanks again for your advice. Eric
<Cheers, J -- >

Engineering And Tweaking Hey Scott, thanks for that fast reply! <Your welcome! I'm glad that I could be of service!> You guys are notorious for responding quickly, and I believe I speak for everyone else when I say that is much appreciated especially when you guys are doing this on a voluntary basis. HOORAY for WWM! <Thank you very much for the kind words! We hope that you enjoy the Daily Q & A's as much as we enjoy helping our fellow hobbyists!>   Anyway, I was actually thinking about going with the Mag Drive pump anyway. A few more questions for you this time Scott. <Sure> I was thinking at first that I wanted to be passing about 1400 gph but thought maybe this was too much current, now I feel more secure. If I were to get the Mag 2400 which has a 4ft. head flow of approx. 1900 gph and a Continuous Siphon Overflow ( not sure of brand name, maybe this IS it's name, > http://www.drsfostersmith.com/product/prod_Display.cfm?siteid=6&pCatId=3642 ) <CPR Continuous Siphon Overflow> Would this be too much flow if I were to do some fancy hard plumbing up top ( my system is all soft plumbed right now; a little scared to attempt hard ) and divert one flow from pump into four or five exits into the main tank? <A nice idea...I'd go with the pump that has the higher flow. If you are hard plumbing a return manifold system, you'd be surprised how fast the head seems to build...Most important, IMO, would be to have an overflow that can handle the pump. I'd go with as large an overflow as possible. I think that the overflow would work...You may want to go with an even larger (like 1-1/2 inches) standpipe...Better to have too large than too small, IMO!> If and when this is done, would I still need the four powerheads ( mostly all 250 gph ) on a Wavemaster Pro running in the tank? Too much flow you think? Your opinions? <Well, you can never have too much flow. Your idea is fine. I actually prefer the idea of diverting the returns into rotating oscillators, such as Sea Swirls. They are better, IMO, because you don't have to worry about heat buildup, unsightly powerheads in the tank, and other problems.> Next, I told you that three of my fish were sick ( Tang, Clown, and Coral Beauty ). There was also a purple Pseudochromis, he died though before I got them out. <Bummer!> These three are in QT with Cupramine on second day. I was told that I really did not need to take the Chromis and the Gobies out because they were not as susceptible to common diseases. True or False? <Well, the fact that a fish may or may not be as susceptible to illness is irrelevant, IMO, if there is disease in the tank! I'd err on the side of caution and get these guys out. You may not need to medicate them, but do observe them in a different tank for a while. Let the main system run fallow, without fishes, for at least a month. This is a successful approach to treating parasitic diseases. Deprive the parasites of their hosts in the main tank, and you'll achieve a higher rate of success in combating ich!> Did I make a major goof, AGAIN? If they need to be taken out I don't think I can take another tank evac. this soon. Can I treat them in the tank with something and not harm inverts and LR? <There really is no such product, IMO! I guess that the best thing to do is to get them into the treatment tank...copper and all. You can follow the manufacturer's instructions concerning the medication dosing, then gradually let the concentration decrease for the remainder of the time the fishes are in the "hospital" tank.> I was going to ask you anyway if I needed to treat the main tank for residual bacteria before the fish go back in. <As above, just let that tank run "fallow" for a while...Hopefully, this should do the trick> I Also told you that I had a major algae prob. right now. I ordered a detritus and algae attack pack from Live Aquaria to combat this prob.. Will it be okay to put these inverts into the tank (there is also a Sailfin blenny included in the algae pack )? Your opinions? <Sure, I'd be okay with adding the snails, starfish, crabs, etc. but I'd avoid the blenny. He is just as susceptible to ich as anyone else!> Lastly....I think, if I take some pics of some unidentified critters in my tank could you maybe help me ID them? There's some cool stuff growing from some of the LR. I it from Pet Depot in Decatur, Alabama if anyone is nearby and interested. It is absolutely the best LR I have seen in my 9 months involved in this hobby. They tell me it is Florida aquacultured rock. It has pink, purple, red coralline; orange sponges; lots of little feather things ( will send pic later ); Halimeda; and some other weird algaes. It is 7 bucks per pound and well worth 10! <You heard it here first, folks...!> I think that I asked enough for you for now, I can't think of anymore pertinent questions. I'm sure that I will have more for you later. So far Anthony and yourself have answered the most questions for me and you guys are the best so far! Thanks again and hopefully you'll let me send you some pics of my tank and critters contained therein. Stephen Baker <We'd love to see 'em! Keep learning, sharing, and having fun in this great hobby! Good luck! regards, Scott F>

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