I did use them on my former sump setup. I was not very impressed. There is not a lot of surface area. And I was always plaqued with the problem of making sure that there was water flow over all the balls. I personally would not use them again, there are just better options. Its hard to beat these canister filter/bio wheel combos.
I just finished setting up my sump system today. I have a few gallons of bioballs in it. As for how well they work, idk firsthand, but i've heard that they are really good. And i thought they were so good because they have a really large surface area .
i got a pack of the coral life bioballs! thought i would try them as i have 3 tray in my new filter to use, i got .....
one box of bioballs
one box of ehfi mech
one box of ehfi substrate
( also a box of bio hex nodes as back up)
wanted them for the bacterial i dont think the coral life ones have the carbon core ??
bio balls meant to give u a greater surface area for bacterial colonisation. my one gallon box stats a surface area of 21.5 sq feet supporting 45-60 gallons. round and black about an inch across ( diameter)
OK cryosi, I would recommend a product called "Cell Pore"
This is a sintered glass bio media manufactured in the US. Kent products have recently imported, and are now distributing this media in jars.
About 5 years ago I found this media on the 'net and imported a large batch myself. It came in sheets 15x12x 1"thick, they also made air stones (guaranteed never to clog) and 1" cubes which Kent now sell.
BTW it cost 10% of what Kent are retailing it now Mac.
Cryosi, for a tropical tank, right? I used the ceramic tuibes when i needed a media system. They work well, and the balls should too. It will take some time to get a good batch of bacteria growing on them.