Question: I have a cycled 55 gal...can I steal the water?

[Graphite]

I am wanting to get a couple Axolotls in the next few weeks, but I want to set up a good tank first obviously. I am planning on buying a 20 gallon long tank, since my 10 is too small and my 30 is too big.

I have a 55 gallon cold water tank with a native black bullhead catfish and a native green sunfish. This tank has been cycled and running for about a year now. Can I take all the water to fill the 20 gallon straight from the 55 and just use it like that? Can I just do that and stick a filter in there and call it good? Do I even need to use new water to start?

Sorry for the confusing questions, I wanna do this right!

 

[Kaysie]

You can use that water as long as your fish tank is healthy.

However, beneficial bacteria don't live in the water; they live on the surfaces of the tank. The best way to cycle your new tank would be to borrow some substrate or filter pads from the old tank, and drop them in the new tank. If you use gravel, put it in a stocking and hang it next to the filter in your new tank. Seeding this way in an understocked tank should be close to an instant cycle.