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Activated Carbon

Jul 24, 2003
If you have a large tub of carbon that has been opened a while ago, many months, and not used, is this ok to use straight away or do you have to 'reactivate'?

Ive heard of people puttin it in the microwave to reactivate it.

Can anyone add anything to this?

I'm not sure if it has a shelf life in the same sense as perhaps something that spoils, but in exposed atmosphere, there's no telling what the carbon may pick up. Though there is much air movement, there is however, some reactions going on with exposure to impurities. I.e., smog, smoke, fumes from the can of whipped topping that was used the night before, etc. Perhaps it's more my paranoid side rearing it's ugly head. :goofysca:
I'm just looking at a carton of activated carbon from Aquariium Pharmaceuticals, and I don't see any expiration date anywhere. I would think as long as it's stored in a cool dry place, closed container, should be fine. I know I've used carbon I've had sitting around for more than a few months and actually never thought about the expiration. I would be interested to see what everyone else thinks.

Carbon that has been opened looses its cleaning abilities a lil as it starts to absorb stuff in the air. "Reactivating" it is more like giving it a wash, as real activation reqires huge pressure (50atm or something) and 900 C temperatures.
I home distill alcohol, and you can get a bit of extra use out of carbon that has absorbed some impurities by giving it a wash in bioling water or in the microwave. Look it up before you chuck it in the microwave.

Cleaning will never get it back to its original state - basicially by using heat you are trying to re-vapourize the molecules trapped in the carbon, and many will, but not all will go. So it gets worse over time.

I would say that with an opened bag you will be fine!!! especially since its only gases absorbed- very likely to re-vapourize, if you wash it.

It's surprising how fast an opened bag of carbon looses its cleaning ability.

It doesnt have a "shelf life" if in a sealed container.

If you are that worried about it dont use it, for peace of minds sake. Personally I would use it after a good washing, - I drink the products of re-used carbon and I'm fine. Well, slightly inebriated!!!!
Ha haa

cheers for the comments

The thing is if you buy in bulk its gunna sit there for a while as you can only use so much at a time cant you.

Well I'll give it go anyway an see what happens, maybe , hmm was thinkin try one time with carbon thats been reactivated in microwave then try next with some that hasnt...only thing is there is so many other factors goin on with the tank it would be difficult to tell I think.

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