Flow question

[sigshane]

Okay, I understand the need for substantial flow for a marine aquarium. I also understand that the total flow rate equals the return pump flow and that of the power head(s) in the tank.

If I have two power heads in the tank, is it advised that I get two of the same GPH rating, or does that matter?

Also, can there be TOO MUCH circulation in an aquarium? I am thinking about getting two 800PGH power heads for the DT, and my return pump is also rated at ~800GPH, but is adjustable.

Is 2x800GPH too aggressive circulation in a 90 gallon FOWLR tank?

Shane

 

[rdnelson]

The rule of thumb on a return pump is 10 x the volume of the tank. But that's a rule of thumb only.

The required flow in the tank really depends on what livestock you are putting in it. Softies generally don't need as much flow. Most Acros need lots of flow. Where you place things can help.

I know that isn't a clear cut answer but it is the right answer. At least as I understand it.

 

[sea atlanta]

Don't consider any flow from your return as tank flow. You want to spec that per your filtration and should be a LOT slower than is generally done by hobbyists.

In tank flow: you'll find that you'll need a lot more than you think. It will all depend on how the tank is aquascaped. The more obstructions you have, the more flow you'll need. Fwiw, we've never seen a tank with too much flow, but I'm sure it could be done.

 

[jbdreefs]

A while ago there was a thread with a poll asking about flow in the tanks. Most people were above 20 x the tank volume and a large portion was above 30 x the tank volume. What you are proposing will be fine. Good luck!

 

[tonymission]

SEA Atlanta;993754 wrote: Fwiw, we've never seen a tank with too much flow, but I'm sure it could be done.

Was going to ask about this-- I have 2 mp40s on a 4' sps frag tank. No rocks in display just some racks and a lot of flow out off the return. Have one mp at about 60% (against the return) and one at around 25% (with the return). You can probably go surfing on top of my tank. Tons of water break and it's actually really loud.

I always have to clean off little water streaks on the outside from random splash over. I've been wondering if I'm pushing it too hard... Vortechs are positioned pretty high so as not to have direct flow on any of the frags.

So there's no such thing as too much flow? Corals are growing but I'm always trying to make sure everything is super dialed in.