How To Switch Filters

so I got a new aqua clear 20 to replace my topfin 10 in my community tank. i'm using the topfin 10 in my 2.5 tank I was planning to get a sponge filter for. I just poured a bottle of tetra safe start into the aqua clear. should I cut the floss off my cartilage, put half into the aqua clear, and keep half in the topfin? i'm planning to change to filter media for the topfin. thoughts?
I also have 10 cpd acclimating right now and I really worrried for a spike or a change.

 

I always run a new filter with the old filter running for about two weeks. If that’s an option for you, that’s the road I’d take. Otherwise, take the old filter media and put it into the new one. You can also go to a LFS and ask for some of their old media if they have it. I’ve done this before. Chain stores usually won’t do this for you though.

 

I always run a new filter with the old filter running for about two weeks. If that’s an option for you, that’s the road I’d take. Otherwise, take the old filter media and put it into the new one. You can also go to a LFS and ask for some of their old media if they have it. I’ve done this before. Chain stores usually won’t do this for you though.

yeah I really need to get the old filter into the next tank. i've tried asking for media at all my lfs but it's always a no.

 

okay so I cut out the floss and stuck it all in my new filter. moved the old filter to the 2.5 tank, and added in cleaned poly fill just to catch debris. I'll be updating the media in there soon!

 

I recently did the same.
Run the new filter with the old one for as long as possible, place the old media into the new filter to help jumpstart the produces and use TSS or Stability to stop spikes