Return blowing bubbles

[mjszos]

Your problem is solved but another thing to consider, if the problem persisted, would be a restrictive grate or small weir on the pump input causing the impeller to cavitate.

My regret with the tank at this point is not replacing the Red Sea valve with a gate... May be due to upgrade that in the future. Thankfully flow to the pump is fine, my sump level may actually be too high at the moment. Problem for another day though :)