Flow rate GPH

What if any is the best flow rate for an aquarium? What is too much, or too little?

 

It really depends on your setup and what you plan to keep. In a FOWLR, you can get away with as low as 5x, or maybe less, depending on the amount of rock and whether dead spots form. For SPS, you usually want 50x+.

 

so for a 50 gal. tank, 250gph would be the min?

 

http://www.3reef.com/forums/reef-aquarium-articles-how-tos/basics-flow-78711.html

 

Not really. You can get away with less. It depends on whether you have a tank with rock or not, and whether you can arrange the powerheads so you get flow everywhere.

Like, if you keep a shark and ray tank, you don't need lots of flow relative to the tank size; there's no rock to deal with.

But if you have a rock wall with tons of caverns that has tons of corals, you should look into more flow.

So, in sum, I'm not going to answer the question straight without some idea of what your plan is for your setup.

 

"50x+" - id like to point out that the turnover rate is not derived directly from the return pump. just for sake of confusion. when i first started people were telling me 50x for SPS and i knew i wanted SPS so i started looking at 1800+GPH external pumps for my 75gal before realizing that I dont want 1800GPH through my sump. so take a sum of all the powerheads + the return when you factor in your overall turnover in the display.

 

That's a good point to make too. Sump turnover is different from total flow rate.

 

one additional point Id like to make based on the amount of changes I have made with water movement in my 5ft

you can get away with a higher total turnover, even in a softie set up, if you use more than one source of flow

over last couple of months I removed 2 x wavemakers both generating 20,000 LPH each
and replaced them with 4 x wavemakers each generating 6000 LPH each

the amount of flow in total has increased, but the amount of water travelling in the same direction at any one location has decreased

thus I am finding it easier to provide/ create conditions suitable for more pieces of coral

basically if you had 10x water flow all coming from 1 direction, you might find that there would be places that some corals would not be happy
if you had 15 x water volume coming from a total of 2 or more directions, you will have less problems finding suitable locations

IME

Steve