I heard somewhere that bio wheels can go bad, Is this true? If it is should I be worried, I let one of my tanks sit apart for a few weeks. I set it up and let it cycle and the params are good for now, but Im wondering if this may be a problem in the future or even now with some unseen pest. The fishies that are in it are doing ok, I originaly bough 4 and one died the next day, the rest seem to be fine for now.
Goodness I ask a lot of questions ....

Thanks in Advance
Kellie

I asked about replacing mine that I had cleaned with vinegar and bleach and these were the answers I got:

http://www.kokosgoldfish.invisionzone.com/...showtopic=47039

Thanks Jen, that helped a lot!