I had some extras that I was floating in my sump for awhile, it worked just fine. I wouldn't float them as a main source, but if you have some that you want to just throw in... not as effective floating as they can be, but still work.
Nice. Thanks. I have an open 75 gallon sump with filter socks, foam pads and 6l of Matrix. Someone game me a 5 gallon bucket of bioballs and i was just going to dump them in but worried they may have an adverse effect.
Keeping the bio balls in a drip tray will encourage more biological growth than floating the bio balls in the sump...........If you are really bored, then grow some plants in the sump.............