How Often Should I Change My Carbon?

[Euphyllia]

I use Rowa Carbon. On the back it says "Contents treats 260 U.S gallons for 3 months". Does this mean 1/10 of it would treat about 25 gallons of water volume for 3 months? I've been using it for a week. When should I replenish it? :~

 

[kvosstra]

Replace the small amount of carbon every 2-3 weeks.

 

[Sfork]

From what I've been told your first carbon should be swapped out after a week (because it's being used up so quick from you not changing it out for a year ) After that you can go once a month.