Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
I have taken bits of media from several tanks, combined these bits into a new set up and stocked immediately.
The donor tank can usually spare up to 25% of its filter media, as long as it is well established so there are more bacteria on all the surfaces of the tank as well as in the filter.
If you do not share any media, nor any other source of bacteria, but do the fishless cycle right it takes 3 weeks.
Depending on how much bacteria you add, and what your final stocking level will be the cycle will go a lot faster, up to and including OK to stock right away.
A planted tank will have a fair amount of beneficial bacteria on the leaves and other plant parts, and the plants themselves are part of the bio filter, so a densely planted tank in the hands of an experienced aquarium keeper can be stocked right away, too.