Powerhead placement problems.

[Azizza]

I have a 75 Gallon tank and am having trouble with my powerheads.

I have a Maxijet 900 and a 1200 in the back corners pointing to the opposite front corners and slightly upwards. In addition, the return from my sump is placed in the middle pointing directly towards the front.

Now here is the problem. When the streams hit int he middle they are somehow redirecting down towards the subtrate and stirring up the DSB in the middle against the glass. I have a big crater basicly. Not to mention the water is clouded a bit. The only way I can keep them from stirring up the sand is to angle them down a bit. But this doesnt' agitate the top of the water like a powerhead should. Any advice on how I can move the powerheads to keep them from doing this to my subtrate.

Do I even need the surface agitation with the sump? Perhaps I should worry about circulation more. If this is the case I will have an easier time of things.

[Aquabucket]

How about using a heavier grain of sand or substrate near the areas of extreme agitation?

[Iceman30]

With the sump, any scum on the top will come off into the overflow. The power heads just need to move the current around the corals for feeding and such. Stonies like lots of current, softies, don't need so much. I put my strong powerheads on the light timer so they shut down during the night and the smaller ones run for current, just like the ocean. I don't have a wave maker and have success with the timer on 1/2 of the power heads.

[Azizza]

Thanks Iceman that is what I was hoping to hear.

Aquabucket, thats for the advice, but I don't like the look of the heavier subtrates.