grump

Hi everyone I just have one quick question I keep reading not too ever replace media in the filter now I have been replacing the activated carbon pac's in my filters is this good or am I doing something badI rinse everything else in water from the tank and fill the cannister with clean water from the tank befor I replace it and start it again...

agabr123

no you're doing the right thing the carbon will expire after a few weeks and begin to leach things back into your tank, so that definitely needs to be replaced. just the media (the filter floss part) does NOT need to be replaced.

grump

Thank you Alex I have read it so much that I thought I was doing a bad thing... I have 2 filters a rena xp2 and fluval 204 on a 75 gal and a 2 month cycle is that too long between changes 1 every month...

Dozey

Depending on the stock you should be replacing carbon every 3 to 4 weeks. A heavily stocked tank 3 weeks, a lightly stocked tank every 4 weeks is fine.

The term that carbon “expires” is common used but not completely accurate. Kept in the container you purchase it in and will last for ever. But once in your filter it begins to absorb toxins from the water. Once the carbon it saturated it will then begin to leach the toxins back into the water.

I have a very lightly stocked tank and a canister filter. I replace the carbon monthly.