i don't think its possbile to experience silence with external pumps, i like a little noise with the tank, tells me thats its working......IMO a silent tank is a dead tank

Being tied into the aquaculture world by profession, I've used plenty of sequence pumps and can honestly say you won't be overly thrilled with it. I might be completely out of line here but isn't a panworld and an iwaki very similiar?

cheers,

kurt