return pump size?

[Canuckgod420]

I've used several quiet one pumps and have never run into any problems....they are quiet and they always restart when I turn them off. I ave used the same quiet one 4000 on my reef for 2.5 years now and I think its a great pump.
My wife has a 34 gallon cube with the quiet one 3000 and even with the 4.5 feet of head it pushes enough water that I dont even need to consider a powerhead.....lots of flow. In fact the flow is so strong through the 10 gallon sump that if I dont use a filter sock we get tons of micro bubbles, but I dont mind, I just change out the bag every 4 or 5 days and my water is crystal clear.