Bio balls, Good or bad?

I've heard goods and bads about bio balls. I want to know more people opinions on them.

 

i think good for a fowlr tank but bad for reef

 

They can be good, they can be bad /DesktopModules/ActiveForums/themes/_default//emoticons/biggrin.gif You will hear people say "They're a nitrate factory!", but I think that's a phrase that's been passed around quite a bit without a lot of thought.......like anything in your tank, they need to be maintained. If you let a bunch of crud and detritus build up on them, then sure, they will produce nitrates. Rinse them off occasionally and they can be really helpful to a tank. They have many different types of pourous media you can put inside balls now that are more pourous than live rock, i.e. you can have more beneficial bacteria living in a smaller amount of space.
Here's some:
Bio ball media examples

 

+1 lol on the nitrate factory, haha

 

They were pretty popular in the early days of the hobby for fish only tanks. If you're running a fish only tank with minimal rock you may consider trying them since you're bacteria colonies will need more surface area than what the rockwork will provide... although I'd say you're probably better off with biopellets than bioballs. If you're running a system with a decent amount of live rock though then there's no reason to be running bio balls.

 

I ran bio balls when I first started my reef 20+ years ago and then stopped using it and went to just live rock, I saw a reef tank in at the Fish Store in Lincoln a couple of months ago that was using bioballs and the tank looked fantastic, so about 2 months ago I got my tickle filter and bioballs out and started using them on my soft coral tank, I was having problems with cyno-red slime in the tank and after I started using the tickle filter the red slime pretty much is completely gone. Not sure if the bioballs had anything to do with it but my tank looks great and no red slime anymore.

 

I have them in my sump only because its a prebuilt sump and if I take them out the water makes too much noise dripping.

 

It depends. I have seen a new trend in minimalistic scaping in reef tanks with more rock going into the sump then the display. I do not see any draw back in using bio balls in this case over LR in your sump.