Cycling with water from another tank

  1. zeble

    zeble New Member Member

    Planning on redoing my tank so I'm setting up another smaller one to keep the fish in for the meanwhile. I filled it with water from the tank I'm redoing, but should I still wait a few weeks before adding the fish? By the way I'm using filter media from a filter i had set up a while ago and haven't cleaned out.
  2. maggie thecat

    maggie thecat Well Known Member Member

    The beneficial bacteria is mostly in the filter media, with smaller amounts in the substrate and on the decor. Using old tank water in the new tank will make the fish comfortable because of matched water parameters, but it won't influence the nitrogen cycle to any meaningful extent.

    So just set up the holding tank using the old filter media and whatever plants and decor fit, and then move the fish in.
  3. OP

    zeble New Member Member

    Ok thanks, that will definitely save me a lot of time :)