Powerhead placement.

[Keith A.]

I know that there are many opinions about how much water movement is needed for a tank (10% on up to 30% of the tank volume/hr and depending on what you have in the tank). My question is can you get away with a lower amount of water movement in your tank (say 10-15%) if you have the powerheads or wave makers strategically placed to where the corals that need the most current are the ones that are closest and in direct line of the powerhead or wave maker?

Keith

 

[melosu58]

I guess there`s no reason to say you cant as long as those corals that need moderate water flow are not neglected. I would have some flow going to the surface for good surface aggitation which will help with aeration of your tank.

 

[Kurt_Nelson]

Actually, it's 10x to 30x... not %.

And yeah... as long as you have the flow where you need it, there's nothing that says you HAVE to have a certain amount of turnover. In fact, you don't even need to give a coral the amount of flow it "needs"... just don't expect it to thrive. Many corals (but not all) will stay alive just fine with less flow than they should have. They probably won't grow much, but they'll be alive.

The "x times your tank volume per hour" rule, like many other rules, gets outdated and not as useful as equipment changes over the years. For example, 600 gph out of a MaxiJet is entirely different than 600 gph out of a Korallia. Totally different beasts.

 

[Keith A.]

Oops.. My bad. I meant times and not %. I've been running at about 13x the tank volume with two returns from the return pump and a small powerhead. Everything seems to be doing OK. I'm getting some decent coral growth but not a lot of the "flowing movement" I'm looking for from some of the corals. I was thinking about getting a slightly bigger powerhead or two smaller ones to increase the flow to 15-20x the volume of the tank. Maybe changing the water movement pattern a bit too.