I just don't think bio balls do a good enough job.
I visited a marine farm in the Hawkes Bay (North Island ) a while back (OK 3 or 4 years ago!) and they had a filtration tower filled with them. You could SMELL it about a Km away (fortunately no neighbours ) They were farming Seahorses, Packhorse Crayfish and Kingfish. The Crays and the Kingies were doing OK but the Horses kept coming down with bubble disease. From the smell their nitrates etc were WAY off. (& no they didn't test it!).
It's under new management now (funnily enough the previous owners ran out of money!!) I have a friend who works there and he tells me they've got rid of the bio balls and the animals are doing much better. In fact I've seen captive bred Horses from that farm for sale in aquarium stores.
I think they are great. I have used them for years and still do.
If not set up right or properly maintained then they can we a waste of space.
They have a huge surface area for colonies of aerobic bacteria to set up shop but it realy is all in the way the water is passed over the balls.
If care is not spent on ensuring that the water passing over the balls is well filtered mechanically then they will soon get clogged and get smelly. So always use a really good pre filter or micron bag. I use the latter.
Also you must ensure an even covering of water flows over them, I always use rotating spray bars.
This bioball tower is about five feet tall and has a rotating bar. Also Around the inside of the tower are shelves to stop the water running right down the tower, it pushes the water back onto the balls.
an octo produces loads of waste.. what is this waste??? messy eaters (left over food) and poo (but you can pick most of the messy food up hopefully) and their poo (but people say this you cant see, its a bit crystally lookin (is this some kinda chemical??) it doesnt sound threatenin
Are we sayin they are large producers of phosphates or what??
Cheers just makin sure im combating the right thing