POLL- Return pump flow?

[Randy Holmes-Farley Verified Community Expert]

I voted at the bottom end. Unless you are using the turnover as driving a substantial part of in-tank flow, I cannot really see the need for such high turnovers.

For those of you who think a 2x turnover is not "sufficient", what do you think is happening to the tank water in 30 minutes that necessitates it be replaced with sump water?

I don't recall ever hearing a strong explanation...

 

[Greybeard]

For those of you who think a 2x turnover is not "sufficient", what do you think is happening to the tank water in 30 minutes that necessitates it be replaced with sump water?

I'd agree with you... though I've always figured 3x as my lower limit. Why? No real reason, just what I've always done. IMHO, the limiting factor would probably be heat. In a cool room, with the heater located in the sump, what sort of temperature difference could occur across all areas of the system? 30 minutes is plenty to see a few degrees drop in an isolated body of water... but, of course, it's not really an isolated body of water. There would be a point at which the heater couldn't keep the system temperature stable, but I have no idea what that point would be. I'm just guessing, but I'd say calc/alk, pH, Ammonia/Nitrite/Nitrate... all would be less problematic with low flow than temp.

My hot tub has a tiny little 1/4" outlet for water coming from the heater. I'd guess the water flow at a couple hundred gallons an hour, max. It's not quite sufficient to keep an 8 person hot tub running at 103f with the top open, outside, during a snowstorm Temp will fall slowly... 1f every 20 minutes or so. It'd probably reach equilibrium at some point, but whatever that point is, it's too cold for me to want to sit in. I get out at 99f or so

 

[NY_Caveman]

My JBJ Rimless 30 gallon actually holds 26.6 gallons of water when accounting for water levels and the water volume around glass and acrylic baffles (21.1 g display, 5.5 g back chambers). It comes with dual return Accela pumps each stated as 265 GPH. The aquarium is not yet up set, but that is about 20x flow out of the box. That is a lot of flow. I will have some loss due to lift (about 11"), two elbows each (90*) and the use of a VCA Random Flow Generator on each return.

The display will also have a small, single gyre that maxes out at approximately 1000 GPH. That will give me the option of up to an additional 40x turnover.

 

[Pelagic One]

My current flow is 6x with 640gph as reported by Apex flow meter on a 100g tank and 30g sump, on this newly-cycled system. I’ve unfortunately got five hard-piped 90degree elbows to DT with 1-1/4” pvc tee’d to two 1” returns up top. Return pump is the Jebao DCP1000 (2640gph rating from Jebao), which I tested to do about 850gph at 100% flow, but things get crazy after that.

At 100% my substrate has given me a recently shaken snow globe, with exposed bottom showing, so I’m okay with 6x/640gph, with return pump being much quieter.

So when we’re talking desired flow rates for reef tanks, and folks are counting their internal wave/gyre pumps, are we simply talking about more water flowing across corals? And not necessarily flow through sump and filtration?

 

[NY_Caveman]

My current flow is 6x with 640gph as reported by Apex flow meter on a 100g tank and 30g sump, on this newly-cycled system. I’ve unfortunately got five hard-piped 90degree elbows to DT with 1-1/4” pvc tee’d to two 1” returns up top. Return pump is the Jebao DCP1000 (2640gph rating from Jebao), which I tested to do about 850gph at 100% flow, but things get crazy after that.

At 100% my substrate has given me a recently shaken snow globe, with exposed bottom showing, so I’m okay with 6x/640gph, with return pump being much quieter.

So when we’re talking desired flow rates for reef tanks, and folks are counting their internal wave/gyre pumps, are we simply talking about more water flowing across corals? And not necessarily flow through sump and filtration?

Right. I added my display flow for what it is worth. I also said it added up to 40x turnover which is not exactly accurate. It is not the same type of flow as my return.

I guess I usually think of it as how much flow my corals would be getting. Of course this thread seems to be focused on necessary flow through sumps, filtration and refugium.

 

[Mark Gray]

On my new build I will be above 10 I think but really not sure I am also above 10. On the new build I will monitor the flow

 

[Hitman]

I have 2 Sicce Syncra SDC 9.0’s for return pumps that are rated for 2500 gph each. After head pressure and having them turned down to 57% each I’m guessing I’m right at 10% return flow on my 240 DT with a 55 gallon refugium and a 40 gallon breader sump. Drain plumbing is 1-1/2” pvc & returns are 1-1/4” pvc chocked down to 4 line-love 3/4” diameter & 6” long each. I went with th ability for more flow with tha options for upgrades to a bigger tank as well as thinking a larger pump turned down would save on the electric bill.

 

[Chris Villalobos]

I voted at the bottom end. Unless you are using the turnover as driving a substantial part of in-tank flow, I cannot really see the need for such high turnovers.

For those of you who think a 2x turnover is not "sufficient", what do you think is happening to the tank water in 30 minutes that necessitates it be replaced with sump water?

I don't recall ever hearing a strong explanation...

I've thought a lot about this. Triton assumes we are using an algae refugium to remove NO3 and PO4 but also possibly NH3. In BRS's experiment with different PAR refugium lights they did find that even though lower PAR refugium lights could reduce NO3 and PO4 to zero they also let more algae grow in the connected display than the higher PAR refugium lights. I would have thought that if there were zero nutrients with one refugium lighting system, than overpowering the fuge with a higher PAR light would have been a waste of money. Maybe something similar is happening with higher turnover?

 

[NY_Caveman]

I've thought a lot about this. Triton assumes we are using an algae refugium to remove NO3 and PO4 but also possibly NH3. In BRS's experiment with different PAR refugium lights they did find that even though lower PAR refugium lights could reduce NO3 and PO4 to zero they also let more algae grow in the connected display than the higher PAR refugium lights. I would have thought that if there were zero nutrients with one refugium lighting system, than overpowering the fuge with a higher PAR light would have been a waste of money. Maybe something similar is happening with higher turnover?

Interesting. If anyone has had a refugium and a chaeto reactor (which has high flow) on the same system, they might have some insight on this. Even an ATS has pretty high flow usually compared to a refugium.

 

[Cuong]

I usually aim for 10x the flow. Heres my logic: I'm running a varios 8 on a 190g system. That's a 2700gph pump. After factoring head pressure loss (about 20%) and the fact that its teeing into a manifold for 2 more peripherals, accounting for an additional 500 gph, that leaves me with about 1800gph. Add in the last most important factor where my math is probably horribly wrong. That leaves me with an actual flow rate of 190gph, perfect for at least 1x the turnover in a hour.

 

[Randy Holmes-Farley Verified Community Expert]

I've thought a lot about this. Triton assumes we are using an algae refugium to remove NO3 and PO4 but also possibly NH3. In BRS's experiment with different PAR refugium lights they did find that even though lower PAR refugium lights could reduce NO3 and PO4 to zero they also let more algae grow in the connected display than the higher PAR refugium lights. I would have thought that if there were zero nutrients with one refugium lighting system, than overpowering the fuge with a higher PAR light would have been a waste of money. Maybe something similar is happening with higher turnover?

I don't think there's any useful data on where ammonia is being oxidized in any normal reef system. I'm hoping that when (if?) the Mindstream comes to market, folks might get some info on how their husbandry practices impact ammonia levels in the display tank.

 

[AlexG]

I am running about 3x/hr or 4x/hr water flow through my displays from the return pump. I feel that the 10x turnover really was more geared towards the times where we did not have high quality water flow pumps available that maintain higher flow rates in the display tank. Also the factor of the tank size can really make a difference on whether or no its possible or practical to have 10x/hr water flow in a display. A 10 gallon tank with a sump would only need 100gph of water flow to be at 10x/hr which is practical using a small pump. On the other end of the spectrum though I have 1200 gallons of display and it is not practical to get a return pump that will push 12,000gph after head pressure to achieve 10x/hour water flow.

 

[ca1ore]

I run nominally 1,375 gph through the sump on my 450 (400 net gallons of water before adjusting for rock/sand displacement) - so a little more than 3x. To get to 4,000 gph is simply impractical given the pump I would have to use. I would concur with the point made earlier about never hearing a really compelling argument for going any higher. At 3x, I get even heating between the display and the sump and surface skimming is good. I cannot really see why 3x versus 10x (Triton as example) would necessarily affect the uptake of nutrients by the algae (similar to the oft held assumption that matching sump flow and skimmer through flow is important - it's not). I wonder if Triton have any data to support their recommendation?

 

[Hitman]

I run nominally 1,375 gph through the sump on my 450 (400 net gallons of water before adjusting for rock/sand displacement) - so a little more than 3x. To get to 4,000 gph is simply impractical given the pump I would have to use. I would concur with the point made earlier about never hearing a really compelling argument for going any higher. At 3x, I get even heating between the display and the sump and surface skimming is good. I cannot really see why 3x versus 10x (Triton as example) would necessarily affect the uptake of nutrients by the algae (similar to the oft held assumption that matching sump flow and skimmer through flow is important - it's not). I wonder if Triton have any data to support their recommendation?

I’ve often wondered th same about Triton. I’m hearing more stories of people walking away from Triton then going to their technology lately.

 

[ca1ore]

I wasn't trying to pick on Triton necessarily, they're just the most obvious example currently. Lot's of approaches come and go - there's a bit of the 'emperor's new clothes' to all of them. I've been in this hobby long enough to remember and to have tried many of them. Some stick around in the entirety, others in part. I think it is good to be cynical and skeptical and to ask, where possible, for data and/or rationale ..... and then decide for yourself.

 

[Sallstrom]

I like the idea behind the Triton method and I like their products. And we have used them for a couple of years at work.
I just wanted to say that you can run a great reef tank with the Triton method even if you don't have X litres per hour through the sump and exactly Y litres refugium size. The idea is to try to get as good water as possible. So I find it a bit odd that many seems to get hung up on litres/hour when it's just a number.

/ David

 

[Hitman]

I’m personally on the fence with it all. As we see in this post there are very few with even close flow amounts and there is a big range. Everyone seems to have a successful tank as well. With that said like I’ve read many many times no two tanks are the same.

 

[coastkid]

How does 20x per hour sound? I've got a Sicee Syncra 3.0 700gph on a 35g cube with the Eshopps cube nano refugium for a sump.

How is the system running? I am about to build a sump using the cube nano and the same return pump you have. I would love to hear your findings or advise.

 

[SashimiTurtle]

How is the system running? I am about to build a sump using the cube nano and the same return pump you have. I would love to hear your findings or advise.

Tank I isn't running now but I'm about to set it back up. Return is a bit strong for the system but works fine. If I had it to do all over, I'd get a DC Jebao return pump.