GPH

[blk822822]

Ok just a quick question......How much GPH should I have for the return pump on my 100 gall reef tank I'm setting up????? Ive hear 3 to 5 times the water volume. And Also to try to stay close to what your skimmer pumps per hour.

 

[senji]

ehiem 1262 perfect pump

 

[blk822822]

Yea sure you would recommend a $160 pump.....LOL

 

[TJL]

Hey Bill, the old (very old) myth that 3-5x the water volume is good or even wise??? Skimmers are no more efficient at 50gph as they are at 5000gph through sump, the only real factor is its pumps gph/air mix/chamber size = reaction time. I'd go with the maximum GPH your overflows can safely handle. My 125g with its two 1-1/2" overflows and two 3/4" emergency very easily handle 1075+-gph and would like it to be around 1800gph or more. In past 20+ of 30 years reefkeeping have had much less problems and/or issues with high-flow sumps/fuges (most macro algaes grow in the surge zone and or reef crest). My first SPS dominant tank a 180g had three Little Giant pumps pushing about 1400gph each, though the six antique Hagen powerheads were only about 300gph each.


Cheers, Todd

 

[blk822822]

I'm thinking about getting about a 1200gph pump and like 3 pumps in the tank for current. I have one over flow and the bulk head will take a pvc pipe with a 1" inside dia. And its on the bottom of the tank so will 1" inside dia. flow 1200gph back to the refuge?

 

[kpiotrowski]

I too believe in high flow sumps and getting as much water to your treatment center as fast as possible. here is why, some subscribe to the theory ( belief...mis conception) if you have a low flow treatment center that it perfectly treats the water and sends pristine water back to the display. for skimming... the main purpose of my point, contact time is only relative inside the skimmer. the display is where the food is decaying and the fish are excrementing etc and you want to get as much of that water down to your skimmer as fast as possible. since a sump is constantly being diluted with dirty water from the display and skimmed water from the skimmer you can say to some degree that the skimmer is not in contact with the dirtiest water possible and that the most effecient place for a skimmer where it will have as much contact with the dirtiest water possiible is actually right in the middle of the display tank.so if you use and extreme example of 100g tank flowing only 100gph in a slow flow situation yes the water in the sump has much more time to be all intamate with your skimmer etc, but meanhwile the fish are poopin upstairs and that poop water is just flowing around in the display building up cuz its only trickling down to the skimmer at 100gph. in a high flow situation say 2000gph on the same 100g tank you are sending all that dirty water to your treatment center to be dealt with immediatley. I think somewhere down the line people got "contact time" as far as skimming is concerned confused with how long water should sit in your sump. The only areas I am experienced with where slower flow rates may be better is through a fuge for the purpose of creating anerobic zones and through a carbon reactor ( there are other reason that I don't employ), but as far as nutrient export with skmmers and macros I say get that skimmer and macro's as much dirty water as fast a you can so they can have their shot at it!

 

[kpiotrowski]

ps. for another example I have a 120g display, 40g sump, and 50g display fuge. I actually have a low flow fuge BUT I have zero issues with excess nutrients so no need to go any faster. elos kits say zero nitrates and photometer say zero phosphates. my problem with the low flow fuge is actually getting enough nutrients to them to keep them alive!!! imagine that for a problem lol. I am lightly stocked with fish compared to most and actually overfeed my tank using the growth of my macros as a guide. I have an iwaki rlxt wich is like 1000gph but not much head loss. I prob flow 85% through the sump and 15% through the fuge. Ok, so I could increase the flow to the fuge to get the macros more nutrient rich water instead of overfeeding, but keep in mind the tests that say zero are done is the display tank water too, the reason I am leaving it the way it is and overfeeding is becuase I am slowly adding more fish. and when I get to a point when I have x amount of fish that I still have low nutrients, macros grow well, and I can feed regular I will know I have a well balanced system.

 

[Peppie]

I dont know how to work the math, but your 1'' drain pipe will only handle so many gph. I would keep the gph 20% less than the max. That will lead you to what size return pump you should shop for.
The high flow / low flow debate has been beat to death with no real winner.

 

[kpiotrowski]

GPM/GPH Flow based on PVC Pipe Size, ie, How much water can flow through Sch 40 Pvc Pipe Size 1/2" 3/4" 1" 1.5" 2" 2.5" 3" 4" 6" hope this works.dave, looks like you're gonna need 8 inch pipe for your tank! lol

 

[Peppie]

Thanks for posting the link Kevin. Hope this will help the OP

BTW I will have 4, 1 1/2'' pipes I can move over 8,000 gph. But will only use a fraction of that. I am a LOW Flow guy. I like to clean the water in my sump, instead of just running A LOT of dirty water thru it

 

[kpiotrowski]

dave, was joking about 8 inch pipe for you closed loops!

 

[Peppie]

My closed loops will be powered by a 5 hp Honda engine with 4'' sch.80

 

[kpiotrowski]

ummm......he's probably not kidding!

 

[colin779]

One thing I noticed, I used to run 1400gph through my sump via two pumps. I would have about 1/4 left on the teeth of my overflow, but I would always have a little bit of film on he surface of the water. I shut down one of the pumps just to test the low flow vs high flow theory. With only running the one pump at 750gph I have no film on the surface of the water, and the water in the display seems clearer.

My tank is a 90 with a 29 gallon sump, running a SWC 160 cone skimmer.

 

[kpiotrowski]

RE: surface film. surface film is not a problem of too much flow rather a a problem with flow patterns. a good way to check your flow patttern is to feed some finley crushed flake food and observe what it does and then adjust your flow pattern according to your preferences. do you want all food you feed droping down your overflow immediatley so you have to shut off your return pump to feed? this is the best flow pattern as far as removing surface film but can also be a pia! I am somwhere in the middle in that the smaller particals I feed take a minute or so to eventualy clear the waters surface. I have a center oveflow and my flow patterns change with the random flow but they usually find thier way on one or both sides of the tank where you will see about an inch wide path that goes all the way down the side and straight though the teeth of the overflow box. when I feed I knock down those pellets or whatever I am feeding that immediately head for the oveflow box so they don't go to waste. This is probably one of the less talked about topics, but a good one I would think, right.

 

[TJL]

Great TOPIC, utilyzing food both suspended and floating to show flow pattern(s) is a very useful aproach in setting up Return and Powerhead placements. I'm a firm believer in the positives of having a Gyre Flow Pattern for most aquarium dimensions in my experience seems to be the best at removing most all detritus and surface films. I either use food particles or detritus from stirring up the sand bed to setup/adjust posistion of Powerheads. In my usual counter-clockwise gyre setup I place powerhead(s) in upper (mid) back left corner and point towards front dead-center, other Powerhead(s) in mid back right corner aiming slightly up towards top back left corner. The main Return is directed from top back center Y'd into central areas to push out any dead spots back into flow. The Gyre rotation keeps things in suspension while its offset angle clears (pushes water to either corner overflows) both surface and bottom water column.


Cheers, Todd

 

[josh88]

Hey thanks for asking your ?, the replies have helped figure out what I'm going to do. And the link helped a lot

HTC EVO

 

[blk822822]

Well I went with a Eheim 1262 pump like 900gph, the 1" drain keeps up good.