How much surface agitation?

[LordJoshaeus]

Does a reef tank need to have violent surface agitation, or would a gentle ripple effect suffice? My 10 gallon is closer to the latter currently and I am considering getting a different pump. Thank you. PS...it is a 10 gallon tank with a 211 gph pump.

 

[Cthulukelele]

A ripple is usually enough, and if your pump is variable speed some variation is helpful especially for certain coral. Watch for fish hanging out constantly at the surface and constantly "yawning" or breathing rapidly. This is usually a sign of low oxygen. It also is always lowest at night, so if it's too low in the day things usually die during the overnight period. Barring huge bacterial blooms, low oxygen rarely kills while the lights are on.

 

[Extremeengineer]

On a small tank like that I’ll assume one return nozxle. You can put a Y in and direct one leg to surface and other somewhere to generate some sort of flow pattern. Especially if you combine that with a larger pump, you can get much better flow in the tank,