Cultured Biologix pHlush Flushing Solution, 64 oz.pHlush is a carbon based agent that releases and dissolves bound up salts and insoluble elements in the nutrient solution. These weak acids complex (attach) themselves to insoluble molecules and release them back into water so they may either be removed from the media or taken up by the plant. Used with every feeding, prevents pH and PPM complications throughout the grow cycle. Used at higher rates, pHlush acts as a strong and effective flushing agent