^My method to estimate the working time is based upon an extremely scientific empirical approach.
First I lift up the tank hood.
Second I tank a sniff.
If tank smells like a pond it's time to switch out the carbon.
I use carbon to remove the volatiles and aromatics from the tank. I started this when my wife was pregnant with my son. Pregnancy amplifies the sense of smell in many women. Any guy having to haul out the garbage 4 times a day for 9 months can verify this.
I've kept it up since then because I've never found another filter media that can keep a 125 gallon goldfish tank crystal clear. It's is a little expensive running me about $15 a month for a tank that size but worth it for being odor free.
First I lift up the tank hood.
Second I tank a sniff.
If tank smells like a pond it's time to switch out the carbon.
I use carbon to remove the volatiles and aromatics from the tank. I started this when my wife was pregnant with my son. Pregnancy amplifies the sense of smell in many women. Any guy having to haul out the garbage 4 times a day for 9 months can verify this.
I've kept it up since then because I've never found another filter media that can keep a 125 gallon goldfish tank crystal clear. It's is a little expensive running me about $15 a month for a tank that size but worth it for being odor free.