Carbon

[davidwillis]

I am trying to figure out how much carbon, what type, and how often it should be changed.

How much:
I know I can go to BRS, and use there calculator, and it says I should use 2.1 cups of rox 0.8 for my 340 gallons of water. It also says to change it every two weeks, but also to monitor.
However would it be better to use less, and change more often? I actually think my current bio load is very low, and would not need nearly this much. Currently my skimmer does not even pull anything out, and I am only using one bag of bio chem zorb, purigen, and a polyfilter. So this also brings up the question, could I use much less carbon when I also use purigen, and a polyfilter?

What type:
From what I have read, it sounds like rox 0.8 is what is most recommended for low dust, and high quality. However I have to say that when I put in the bag of bio chem zorb, it made the water clearer than I had seen before, and the bags make it very convenient. I think I would just use a bag of it every week (two or more bags if I notice one is not enough to keep it clear). However I can't find any information on the carbon used in bio chem zorb. Is it acid washed, etc. I am very afraid of getting HLLE using bad carbon (I have experienced this in the past using a lot of dusty carbon). In fact I have been considering only using purigen and polyfilters due to the possibility that carbon may contribute to HLLE. However I don't think purigen and polyfilters will filter out everything carbon does...?

How often to change:
Would it make sense to use say 2 bags of bio chem zorb, replacing one each week in a rotating fashion. This way there would always be a fresh bag, but I would also fully use the carbon before replacing? Or if I used rox 0.8, I would need to put it in bags so it would be easy to rotate them out (these would be inside a reactor).

[Sk8r]

Carbon can be overdone. I generally never use it unless I have a specific problem it can solve and after it's done, I quit. The biggest problem with carbon is that it saturates with the absorbed problem and then starts breaking down and releasing the problem back into the tank. If your other medium suffices, I'd use it. The one thing carbon does well as a general fix is removing organics like the angry spit of soft corals.

[davidwillis]

Originally Posted by Sk8r

Carbon can be overdone. I generally never use it unless I have a specific problem it can solve and after it's done, I quit. The biggest problem with carbon is that it saturates with the absorbed problem and then starts breaking down and releasing the problem back into the tank. If your other medium suffices, I'd use it. The one thing carbon does well as a general fix is removing organics like the angry spit of soft corals.

I generally have the same view on carbon as you, and was not even planing on using carbon with my tank. However I really love to have the crystal clear water with carbon, it is cheap (compared to polyfilters or purigen), and it is very easy to change out (compared to regenerating purigen). I also use it to keep the smell down, which is a big concern, and I am not sure if purigen and polyfilters will do as well with odors.