PDA

View Full Version : Activated Carbon Capacity


ReefJaws
05/12/2018, 12:54 PM
Do different types of GAC share similar capacity and differ primarily in capture rate and pore size, or does capacity vary greatly too? I'm considering running a large amount of less efficient bituminous to extend maintenance intervals, but still achieve capacity and sufficient capture rate through bulk quantity.

Frogmanx82
05/12/2018, 01:23 PM
Capacity is certainly dependent on the type of carbon and what you are removing. Its all about pore size and surface area, not necessarily bulk weight.

bertoni
05/12/2018, 03:43 PM
They vary quite a bit, and carbon products are targeted for different purposes, as well. Some are for filtering air, others for water, or at least liquids. I'm not sure why you'd want to use a less efficient media other than cost. I don't think it's going to last longer, given an equivalent filtration load. Trying a larger amount of carbon might help, but that's not clear. The carbon can become clogged or channelize. You'd want a reverse flow reactor with a carefully tuned flow rate for that approach.

Dan_P
05/12/2018, 04:10 PM
Do different types of GAC share similar capacity and differ primarily in capture rate and pore size, or does capacity vary greatly too? I'm considering running a large amount of less efficient bituminous to extend maintenance intervals, but still achieve capacity and sufficient capture rate through bulk quantity.

Goooood questions!

I have not seen a scientific study comparing adsorption capacity and rate of removal for marketed GAC’s. The established fact about carbon is that it does a good job removing the yellow color that can develop in aquarium water. What else it is removing is conjecture and whether removing it is all that important is debatable. I use carbon as cheap insurance.

GAC capacity probably can last months at 1-2 cups per 100 gallons for a reef tank, maybe less for a fish only system. Packed GAC columns tend to accumulate detritus that cause them to become clogged and resistant to flow before their capacity is spent. If the bed is too loose and flow causes particles to tumble, the particles can breakdown to dust and get all over.

Hard to advise you, except to say that GAC is cheap and can last months. This might not be an area to spend too much time worrying about.

RobZilla04
05/14/2018, 07:01 AM
Try looking through some old thread for which brand has the least "dust". Every time I run GAC it's a pain [profanity] to rinse until the water runs clear through the mesh bag.

I believe the BRS brand was voted to be the best for this, but double check.

clevername
05/15/2018, 09:17 AM
https://www.youtube.com/watch?v=JP5Vu6OvLOI

here is a good BRS video