Bio Balls-Good or Bad

I know bio balls are bad in a reef tank, what makes them good in a freshwater? Surely nitrates need to be kept low in a freshwater to avoid algae blooms also, I'm confused.
 
I know bio balls are bad in a reef tank, what makes them good in a freshwater? Surely nitrates need to be kept low in a freshwater to avoid algae blooms also, I'm confused.

I've always wondered thesame thing. If bioballs, wet-dry, sponges, etc. are nitrate factories in SW, why not in FW?
 
I've found Chemi-Clean to work very well to erradicate Cyano.
 
My tank has up and running for a little over four months now and i am using a wet/dry. I know that is not very long , but so far so good. My water params are perfect and have had no problems keeping them that way. All of my corals are healthy and growing. Like grins said they are not a problem as long as they are maintained. Pre filters make this a much easier task. I have my water running through two pre fiters before it gets to the bio balls and hav'nt had to clean them yet. You do have to clean the pre filters regularly though(every 3-5 days). My lfs runs their whole system on a HUGE!!!!! wet/dry system and they have no problems. They even keep sea apples in all their tanks just to lett people know how well they maintain their water params.
 
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