Switching from Tropical to Coldwater

[labmad]

I am going to turn one of my juwel rio 180's into a coldwater tank, but just wondering if i have to leave the tank running with no fish in for a while or once the temps are ok, will it be fine to add some fish.........

didn't know if a re-cycle was necessary or if the bacteria that has built up would be detrimental to coldwater fish with it previously housing tropicals?

It aint the biggest tank but was thinking of a couple of fantails in there and some plants possibly

cheers

[Trillian]

The same filter bacteria occur in both tropical and coldwater tanks so all you have to do is remove the heater, do a water change to refill with cold water (quicker than waiting for the water to cool down) and then add the goldfish.

[labmad]

Originally Posted by Trillian

The same filter bacteria occur in both tropical and coldwater tanks so all you have to do is remove the heater, do a water change to refill with cold water (quicker than waiting for the water to cool down) and then add the goldfish.

Nice one - thanks