Has anyone ever tried these Bioballs in their saltwater filter?

They can work fine. They do need to be cleaned periodically but that is no big deal. Yes, they can become nitrate producers but only if you don't clean them. The proper process for cleaning them can be found here:

http://saltaquarium.about.com/cs/nitratecontrol/ht...

Saltwater aquariums need a good skimmer but that is no substitute for good biological filtration.

I would want to have 2 pounds of live rock per gallon of tank size as well. I use bio-ribbon in my tank and my nitrates are consistantly zero.

I don't recommend bioballs for SW aquariums. they can and will become a nitrate factory. A better option would be to replace the bioballs with live rock or live rock rubble.

They are really not very good for reef tanks, as they can become nitrate factories if they aren't cleaned out regularly...and cleaning them all can be a major pain. They do work in Fish only tanks though, as a mechanical filter and eventually biological as well.

i wouldn't recommend using them. better off just using a really good skimmer and you can use a filter sock for removal of debris.

there more a pond filter medium and not really any good for a tank.