Start a new tank with old water?

[Deadna]

My younger sibling just recently got a 10 gallon tank. He really wants fish sooner than a month from now, and I was wondering if I put water from my 30 into his 10 during a water change, would that already be cycled? Or would I still need to wait for a normal cycle? And will adding a dosage of aquarium bacteria help at all? Thanks!

 

[Fishlover3578]

Probably best would be put an xtra filter in your tank for a few weeks then put it in your brothers ten gal immediately as fast as you can.

 

[Deadna]

I have a Marina i25 running as extra filtration in my 30g, and he has a RENA smart flow 20 ready to use for his. If I put both the Marina and his RENA together in, would that give it the bacteria?

 

[Fishlover3578]

I would think so and then just keep a close eye on his tank

 

[molliwopp]

If you have 2 filters and put one of them straight from your tank to his, its will be ready for fish. You would have to leave it there for a couple of months until the other had cycled, once you remove it, he needs to keep an eye on water parameters for a week or 2.

 

[Deadna]

Got it. So I'll leave them both in there until the bigger one is biologically settled.