Quick question

[BobB]

I have been reading up on RO/DI systems and I have seen they use carbon based filters to remove chlorine. It has been mentioned on this site that carbon shouldnot be used in the filtration systen because it could harm the discus.

[pcsb23]

Yeah, it takes a bit of explanation to understand. The problem with carbon in a tank filter is that the water in the tank passes through it many times in a day, so the carbon gets to act on it many times in the day. With RO/DI water it only passes once or twice over carbon. So in the tank it gets many chances at removing trace elemenst etc as well as harmful stuff. Carbon itself is not a bad thing, over use or inappropriate use is the problem.

hth,

[RyanH]

Beside removing the trace elements that are important for a fish's healthy, the other problem with carbon is that it is also easily forgotten. After a few weeks, If it's not replaced, all of the impurities that it has been removing from the water, it suddenly begins to dump back in.

[pcsb23]

Beside removing the trace elements that are important for a fish's healthy, the other problem with carbon is that it is also easily forgotten. After a few weeks, If it's not replaced, all of the impurities that it has been removing from the water, it suddenly begins to dump back in.

And with dire consequences too!

[Cosmo]

RO/DI carbon cartridges all have a rating as to how many gallons of water they can treat at "x" amount of chlorine before they need to be replaced. If the cartridge isn't replaced often enough, it not only has the potential to leach bad things into your storage tank, but it will allow chlorine/chloramines through which will destroy the membrane. I always make sure I change mine well before I reach the max possible rating... just to play safe.

And don't forget to account for the waste water when calculating how many gallons have passed thru the carbon block

Jim