Thanks for the reply FJ . I know that it will help keep standing water fresh longer if you put a small piece in there and i know they use it in water filters and air filters . It even has a detoxifying effect if you eat small amounts of it (dont try this at home kids).
If i was running soil i would try it and let everyone know how it went but i run straight pearlite and they already leach pretty easy .
I found this information on a website of an activated carbon dealer;
While charcoal helps to clean the soil of pollutants, it also acts as a soil conditioner. It is used as a top dressing for gardens, bowling greens and lawns. Charcoal also acts as a substitute for lime in soil additives because of the potash content, and it can be a little cheaper than lime. It is used for potting and bedding compounds as a soil and mulch sweetener, and as a fertilizer and insecticide for roses. Some orchids seem to love it. One study showed that adding charcoal to the rooting medium of peas produced a marked increase in the weight of the pea plants and in nitrogen fixation by the plants as compared to controls. It is suggested that the benefits derived from charcoal are due to its adsorption of toxic metabolites that are often released by plant tissues, especially when the tissues are damaged. Charcoal is indispensable in rye grass seed production.
“While charcoal helps to clean the soil of pollutants, it also acts as a soil conditioner. It is used as a top dressing for gardens, bowling greens and lawns. Charcoal also acts as a substitute for lime in soil additives because of the potash content, and it can be a little cheaper than lime. It is used for potting and bedding compounds as a soil and mulch sweetener, and as a fertilizer and insecticide for roses. Some orchids seem to love it. One study showed that adding charcoal to the rooting medium of peas produced a marked increase in the weight of the pea plants and in nitrogen fixation by the plants as compared to controls. It is suggested that the benefits derived from charcoal are due to its adsorption of toxic metabolites that are often released by plant tissues, especially when the tissues are damaged. Charcoal is indispensable in rye grass seed production.
Here are some planting tips using charcoal chips. Start with a plastic liner in a tray. Add half an inch to an inch of gravel in the bottom for drainage. Next, sprinkle enough charcoal chips to cover the gravel layer. Charcoal will help keep bacteria at bay. Top this with potting soil and add your plants"
So i guess i answered my own question but still dont know the specific details on how it works with canabis plants. But from what ive read it definately would not hurt them.