How to avoid a mini cycle with new filter?

[AJ_117]

I recently decided I was going to upgrade the filtration on my tanks; my 29 gallon currently uses an Aquaclear 30, which I want to upgrade to a 50. My 10 gallon is going to get the 30 I currently have. How do I avoid a mini cycle when changing the filters in these two tanks?

I'm also completely changing the substrate in my 10g, should I wait to do that? Thank you.

 

[ImACoolguy]

Just run the old filters with the new ones for at least a month to cycle the new ones.


Caleb