freak78

What's the best way to change the filter on this unit? I don't just want to put a new one on and lose my bacteria. I don't think there's enough bacteria on the bio wheel to keep the tank happy with a filter change. I already made that mistake once. It's due to be changed in a week and I don't want to put my tank in another mini cycle. It say's to change every 2 to 4 week's, I'm coming up on 4 week's. I was thinking of stretching it to 6 week's.

Jaysee

IME there IS plenty of bacteria on the wheel to maintain the cycle. If you are concerned you can cut back your feeding after switching cartridges, to minimize ammonia production.

kcarmartinez

You don't really have to change it that often. Change it if you notice the filter floss getting clogged and slowing down the water. Really the only thing that would need to be "replaced" is the carbon since that doesn't last long. But with aquarium maintenance you don't really need that at all anyway.
Dr. Fosters and Smith makes Bio3 Filters cartridges that will fit in this filter. They come with a frame and sponge that you keep in it, you just change the "carbon bags" that are quilted to eliminate the "tea bag" effect. http://www.drsfostersmith.com/produc...0&pcatid=13370
Unless you need new carbon or the floss is really worn, you could also rinse it in tank water to reduce the debris and put it back in.

ruthven78

I just picked this filter up myself to put on my son's 20gal tank. There are two slots for filter cartridges. I had a couple plans. First I thought about using dual filter and replacing them on a rotating basis. I would put the first one in the back, then two weeks goes by and I would put the second one in, then at the end of another two weeks I would take out the one furthest in the back and move the front one to the back slot and put a new one in the front slot., and then repeat every two weeks. This would give each cartridge 4 weeks of run time with the benefit of having a 2 stage filters. The cartridges cost around $4-5 each though.

My second though was to put the cartidge in the furthest back slot, and in the space between it and the spillway, putting in a AquaClear Biomass insert in the extra space.

The biowheel is what actually provides the biological filtration and they say to only replace if damaged.