All the tanks have been up and running for anywhere from 6 months to 2 years, so the filters are well established. However, 2 of the filters contain the wrong media in them - the proper media is simply a small square sponge that fits the filter perfectly. Now, I've had these filters for many years with many bettas, and at some point the media on 2 of them got tossed - probably cause a fish died of something nasty and I just tossed out everything in the tank. So I have some junk media stuffed in 2 of them but I don't feel it's doing a good job. I bought some nice sponges today and I'd like to use them in these filters, but I'm not sure how to do this without disrupting the cycle.
There may be room to keep a tiny bit of the old media in with the new sponges, but I'd be losing most of it. And I will be squeezing the heck outta the old stuff to get the bacteria into the tank and onto the new sponges. But will it help to toss the old stuff (just floss and odd bits of sponge) into the tank itself and just let it lay around on the bottom for a while? Any other suggestions?
If there's no way to do this without disrupting the cycle then I simply won't do it.
Is there any way you could fasten the new sponges to the intake of the filters? That way they would get the good stuff before the actual filter part of the filter and get well seeded. Or if that might wreck the new sponges do it the other way around and use some of the old stuff on the intakes to keep it alive while the sponges get seeded.
If you just float the old media some of the bacteria might die as the interior might not be getting as much oxygen as it used to. Dropping the new sponges in the tank would be my first choice if you cannot fasten stuff to the intakes and then switch after a couple weeks, install the new sponges and float the old media for a while.
That sounds like it might work. The intake is just slots on the side bottom - I could attach some of the old filter floss to one side of it I think - maybe with a rubber band. That would still leave the other side and the bottom open in case the old stuff impedes the intake rate. Thanks.