Oh my someone told me once a week! PM me if this is too much...

who was that.....LFS?:razz:

monthly for me too

Once a week isn't necessarily a bad thing but to me its a waste of carbon, I change monthly or if the tank is looking kind of scuzzy I"ll change it more often than that, never more often than 2 weeks.

Anyone use Chemi-Pure?

Lol was the LFS, i will do it every two weeks and see how it looks

Yep I've used it, can't say I see any better results than regular carbon though. The chemi-pure elite is supposed to have a phosphate remover in it, I haven't tried it though.

I like to use carbon and purigen. Not 100% sure how purigen works but before I started using it my ammonia/nitrate levels fluctuated daily and since I added purigen it's been at 0 for a long time now. I was gonna test it again by removing my baggy for a week and see if there were changes. On a side note I do a daily 2Gallon water change and a 5Gallon water change on weekends for my 40 Reef so I'm not sure if that plays a factor with fluctuation. Tanks starting to look real good now though so I'm happy with my regime.

I change once a month. However, I think it might vary depending on if you use carbon in a reactor or in a bag.

I just have a bag hanging in my sump and my thinking is that rate of flow through it is lower so once a month is fine. If I had a reactor, I might rethink that.

I haven't entirely convinced myself this thinking makes sense yet though !

Interestingly enough, if you read what the carbon people say, they say to only use carbon intermittently in a marine tank. I think 99%+ of people here run it full time.

There have been reports that too much carbon use can be a contributing factor to HLLE, but I use a fair amount of carbon and I've never experienced HLLE.

Once a month for me too. Just run it passively in a filter bag.