Proper pump for OC 354

[amazingamazon]

Hello,
I have had a successful 75 gal. with a sump system with discus,tetras, ancistrus.

To eliminate some of the noise from the sump(which by the way was powered y a mag-drive 9.5.-I went with an Ocean Clear 354( the canister that can be backwashed)

I powered the OC with a Quiet One 4000.

All seemed O.K until I saw neon tetra swimming near the surface trying to gulp O2.

To remedie the problem,I quickly installed a powerhead to sponge filter and ran an airline to the powerhead.

All is O.K.-But here is the ?

Do I need a different pump(which is located before the pump intake) Or am I stuck listening to the bubbler?

Thank You

 

[squint]

Could the fish have been in respiratory distress due to ammonia due to removing your established bio media?

Sometimes I've had to add powerheads with venturis to my tank with an Ocean Clear 354. Those tanks may have had other issues so I'm not sure the closed loop filtration was the true cause. They'll certainly not oxygenate the water like a sump though.

One option is to put a venturi on the return line after the Ocean Clear. That might not actually be any quieter and might reduce flow quite a bit though. There may also be a flood hazard if the line to the venturi isn't above the tank's water line when the pump is off.