What should flow be in a 55 gallon tank?

[JingoFresh]

I measured my flow in GPH last night going back to the sump, and it seems to be about 65GPH.

For a 55 gallon, is this far too low?

What is an ideal flow rate on average?

Would I need a circulation pump?

[JMorris271]

What size is your drain pipe? http://reefcentral.com/calc/drain.php

Usually,3 to 5 time the tank volume. Some do more

[ca1ore]

Flow between the display and sump is really about only two things: ensuring consistency of heating/cooling and proper surface skimming. Running about 1x tank volume IS on the low end, and I'd suspect is affecting surface skimming. I think you need to run it up to the 200 gph range. Regardless of flow through the sump, you should be using in tank power heads for water movement.

[JingoFresh]

Is it a possibility of my return pump not being powerful enough?

I want to add an octopus eventually(not for at least 6 months or a year till I'm confident I can handle it) and want to set it up for that.

The in tank circ pumps might be a thing of curiosity to it...would there be another solution?

Perhaps a larger overflow?

[JingoFresh]

Is there a way to calculate what flow should be?

I've read other people saying flow should be at least 10x the water volume, is this true?

[kenman345]

Originally Posted by JingoFresh

Is there a way to calculate what flow should be?

I've read other people saying flow should be at least 10x the water volume, is this true?

In a FW tank, the recommendation is about 5x your water volume per hour should be circulating

In a SW tank, I have heard anything from 8x to 20x the water volume per hour should be in circulation. A lot of manufacturers seem to rate SW vs FW as double FW to get SW needs. I have seen this for Filtration units and powerheads.

The main thing is you ABSOLUTELY need some amount of circulation in the tank. I think most people would agree that 10x is a good place to start. I have my tank running around 20x during the daytime and around 8x during the nighttime. I am using my Reefkeeper with an APC module to control the speed of the pumps. I am using two Jebao WP10's and 1 non-controllable powerhead from Hydor that just breaks the surface at the top of the tank to provide aeration. The Hydor is a 425 GPH pump, the WP10's are rated for 530 GPH - 1000 GPH. I have it set for both pumps to run on a cycle between 78% - 60% during the day. at night those values get halved for each but still run in the same cycling. It is something I am still playing around with but the fish seem absolutely fine with this amount of water movement, so I am quite happy for now. I may lower them to run at 70% - 55% in the daytime, but I want to make sure if any one pump breaks, that even at nighttime the other one will provide sufficient water volume flow for the fish to exist comfortably.

I am also considering getting more controllable powerheads in the future (hoping the Tunze Nanostream controllable is cheap like the uncontrolled version they showed at InterZoo).

If you made it this far, you would say, man, you already have a lot of water movement, and yes, i likely do, but I am also trying to make sure I set the tank for a failsafe if it ever has only 1 pump running since I rely on two pumps as the main units for water movement. The main thing is to make sure to now allow any deadspots for the water to sit in and algae and debris to gather in the tank, usually this is a hard to reach spot as well.

So to recap:
- around 10x water volume per hour should be fine
- make sure you have no deadspots, the fish can usually handle a little more flow in areas and they may even try riding the stream every once in a while (clownfish especially)

[pyithar]

the rate of the return pump from sump should be 3 to 5 times the display volume depending on the size of the sump. in your case:
55G*3=165 gallon per hour to
55G*5=276 gallon per hour.

for the water movement in your display, you need the rate about 20 to 30 times the display volume (50+ times for SPS tanks). that's accomplished by using additional powerheads.

so for your 55G*20=1100 gallon per hour
assume you have 165 gallon per hour from the return pump, then

1100-165= 935 gallon per hour

therefore, you'll need additional powerheads that will generate water movement with the rate of 935GPH.

[JingoFresh]

Thanks, I've bought an 800gph and a small 600gph one.

[JingoFresh]

So I put in both power heads, the 650 and the 800. Not sure if my critters are happier or notice any difference.

I would estimate my flow at the moment is about 30x...is that too much? Would I be better off with say two small 500gph ones?

[Donkeykong]

That should be a good amount of flow for a open tank, look all around the tank and see if you have any dead spots, places where there is little to no flow at all. If you do those are going ot be problem spots were algae and junk is likely to build up.

[JingoFresh]

Originally Posted by Donkeykong

That should be a good amount of flow for a open tank, look all around the tank and see if you have any dead spots, places where there is little to no flow at all. If you do those are going ot be problem spots were algae and junk is likely to build up.

When you say open tank, do you mean without a lid?

Can't really see any dead spots..everything looks good from what I can see.

[Donkeykong]

The rock work is what i was talk about. If you have a huge solid rock wall then you will need alot more powerheads to be able to keep good flow around the rock, but if the rock work is nice an open with arches and good spacing then you wont need as many to achieve the good flow