I understand why you use it toney, but i have really gone away from the hassle and fuss of any sort of carbon additives, now i'm just using ADA aquasoil, low dose macro and trace ferts, and very high filtration with surface agitation to increase the speed of gaseous exchange to ensure almost a constant 3ppm of C02. the plants tend to lean on the aquasoil as buffer zone for nutrients, and i have most success growing species with good root systems, can't grow stuff like HC.