Changing hanging filter wool

[ah_hup]

if change to a brand new wool to put in the filter den all the BBs' from old cotton wool gone how?? can clear my doubts?

[AquaObsession]

Yes, the new cotton wool would require some time for the BB to colonize it.

[ah_hup]

but during tt 'some time' will the fish be affected?

[AquaObsession]

if your tank is mature enough, the BB will colonize fast.
I would suggest you keep one old wool in the filter when u clean it. Then next time, you replace the old one with a new one, and same for future maintenance.

Hope you get what I am trying to say

regards
Christophe

[fi5hkiller]

or when you need to change wool, dun wash the filter box or pump.. there will be some left in the box to grow.. and as mentioned above, if ur tank is fully matured, it will regrow very fast and you will experience a slight cloudy for a while..