Transfering DSB

[EmilyB]

Assuming the question is more with regards to tanks that are set up for more than a few months..... be careful. Disturbing the sandbed at all, is a guarantee for cyano or diatoms IME, even when fish are doing it. It is black areas that would concern me most. I never have these, however, I have seen them in other peoples tanks (black=sewer). I certainly would allow for a recycle period if things are smelly.

FWIW, when we did the change here from the 72g to the 120g, I basically laid new sand and topped with old.

The fish all went in that same nite, but we are talking 120g here and not a nano.