rustiscool
New member
Forgive me if this is a dumb question, but is it okay to use an already cycled filter? I've already cycled a tank for my goldfish and am moving him up to a bigger tank, and now I want to use my goldfish's old filter for my axolotl. Can I use the filter that already has all the good bacteria, or should I sanitize it and start the process over? I guess I'm just worried there might be something from the goldfish that could hurt the axolotl.