Changing filter on a cycled tank

[redryder]

My planted tank has been running for about 8 mths, and I want to change my current powerhead filter to an Eheim aquaball. Since there are bacteria on the plants and gravel, can I just put the Eheim in and run it? Or should I run both filters simultaneuosly for a few weeks?

My tank is 1.5ft, and there are currently only 3 fishes inside - 1 betta and 2 clown loaches. I suppose the bioload should be low enough to take out the old filter?

[bossteck]

If you can, no harm doing a parallel run of both filters for a while before removing the old one.

Otherwise, you can consider seeding your new filter media with some of your old media, just put some of the old media into your new filter.

You're right, beneficial bacteria grows everywhere in your tank, and given your rather low bio-load, you probably can't go wrong either way.