Surface Agitation

Just wondering which is needed more a rip/chop at surface or additional current below surface.

 

Great question. Both--really. Surface agitation is important because it assists with gaseous exchange, and it prevents the buildup of scum that otherwise inevitably manifests itself like an oilslick there.

Copious water movement below the surface is required in coral tanks as well--as this helps bring food to corals (although most we keep are photosynthetic), but more importantly helps to flush away waste products. Additionally, water movement helps get waterborne solids like detritus and uneaten food to the sump or mechanical filtration where it can be removed instead of becoming waterborne contaminants in solution.

Again--good question!

 

I have my water return tubes at the surface of the water so that there is good surface agitation.
Then I have my powerheads in the middle to lower part of my tank for the flow below the surface for corals, algea, etc

But like Sparky said....I think answer is both

 

Thanks Sparky a friend just noticed some bubbles under one of my rocks trying to reposition ph to blow them away.

 

If you put your return line at the top the water would just be going back into the overflow! i try to keep the direction of the return pump as far away from the overflow as possible haha