How much flow for 180 gal tank

Jvesche20 · Sep 23, 2019

I’ve never really understood how much flow I’m supposed to have depending on the tank size. I usually tell my LFS what I have and they hand me something. I’m building a 180 gallon tank. Size is 6’x2’x2’ I wanna see what size pump and what size overflow I need. I want an all sps dominated tank. I would like a high turn over rate. What are the numbers I’m supposed to have?

Billldg · Sep 23, 2019

Overflows are usually dictated by the hole that is cut into the tank. As far as turnover, the general rule of thumb for a SPS dominant tank is 40 plus turnover. To get that you need roughly 7200 gals per hour turnover, now you don;t want to get a couple of pumps and run them at 100 percent because you will wear them out prematurely and you will also be blasting the corals that are inline with the pumps. So, for instance, instead of having 2 MP40 pumps at 80 to 90 percent , you would buy 4 MP40s and run them at 40 to 50 percent. You can do this with any pump, I just used MP40's as an example.

jsvand5 · Sep 23, 2019

I have a 210g with similar dimensions. I run 2 maxspect 350s on each side and then one cheap Chinese wave maker on the back wall near the bottom. The flow that I get from the return pump is negligible and doesn’t really do anything for the SPS.

Jvesche20 · Sep 23, 2019

Billldg said:
Overflows are usually dictated by the hole that is cut into the tank. As far as turnover, the general rule of thumb for a SPS dominant tank is 40 plus turnover. To get that you need roughly 7200 gals per hour turnover, now you don;t want to get a couple of pumps and run them at 100 percent because you will wear them out prematurely and you will also be blasting the corals that are inline with the pumps. So, for instance, instead of having 2 MP40 pumps at 80 to 90 percent , you would buy 4 MP40s and run them at 40 to 50 percent. You can do this with any pump, I just used MP40's as an example.

Makes sense so would 2 1.5” holes cut into the tank for the drain be sufficient?

Jvesche20 · Sep 23, 2019

jsvand5 said:
I have a 210g with similar dimensions. I run 2 maxspect 350s on each side and the one cheap Chinese wave maker on the back wall near the bottom. The flow that I get from the return pump is negligible and doesn’t really do anything for the SPS.

I plan on getting mp40s on the sides and maybe throw my other 2000+ gph power heads in there also

lpsouth1978 · Sep 23, 2019

I have 4 x Jebao CP-150 crossflow pumps. One on each end and 2 on the back wall. I run them all @ about 50% power. My tank dimensions are 72x24x26, so nearly identical to yours. My return pump is not adding much to the flow, maybe 600-800gph.

jsvand5 · Sep 23, 2019

lpsouth1978 said:
I have 4 x Jebao CP-150 crossflow pumps. One on each end and 2 on the back wall. I run them all @ about 50% power. My tank dimensions are 72x24x26, so nearly identical to yours. My return pump is not adding much to the flow, maybe 600-800gph.

How long have you had the jebao’s? I was thinking about grabbing one for the back wall. Are they quiet?

Jvesche20 · Sep 23, 2019

So does the return not matter than much? Really just the powerheads?

lpsouth1978 · Sep 23, 2019

They are VERY quiet until about the 80% mark, then they have a slight whine to them. I have only had them about 6 weeks, so can't speak to long term use yet. I had one in my 40b, but it was WAY to much and chewed up an anemone (twice).

lpsouth1978 · Sep 23, 2019

Jvesche20 said:
So does the return not matter than much? Really just the powerheads?

Flow through the sump is generally much slower than flow in the tank. As long as the flow through the sump is enough to remove all of the particulate and turn water through your filter media a few (5-10x) and hour, you will be good. The rest of the flow is provided by powerheads.

Billldg · Sep 23, 2019

Jvesche20 said:
So does the return not matter than much? Really just the powerheads?

Pretty much, my concern with 1.5 in drains is it would be major overkill. I have a 120 gal tank and run 1 in drains and returns and my drains r throttled down with the ball valves.

Jvesche20 · Sep 24, 2019

Billldg said:
Pretty much, my concern with 1.5 in drains is it would be major overkill. I have a 120 gal tank and run 1 in drains and returns and my drains r throttled down with the ball valves.

overkill would make it super loud?

Billldg · Sep 24, 2019

Jvesche20 said:
overkill would make it super loud?

On my tank, if I open up the ball valves on my drains it does get loud.

As it has been said previously, your main turnover is done with the powerheads and not your return pump, all that does it make sure water is going thru your sump.

lapin · Sep 24, 2019

Jvesche20 said:
overkill would make it super loud?

NO. You control the flow thru your overflow with return pump speed and a gate valve inline to the sump.
Most overflow styles can be made silent.
If 1.5 is the hole size in your tank, a bulk head that fits in that hole will require a pipe smaller than 1.5

How To Select and Properly Install Aquarium Bulkheads

Bulkheads allow you to transfer water from one side of an aquarium to the other and allow for traditional PVC plumbing to be connected. In most aquariums, bulkheads are used for drain and return pipes on your display tank but can be used for many other things too. Some tanks come pre-drilled for...

www.bulkreefsupply.com