NATURAL DOWN pH An new concept in pH control. A blend of Good things from Earth and Sea for a crystallized pH adjuster. No more messy , harsh liquid handling. For soil, soilless, hydroponic, hydro-organic and foliar applications. For use with organic and synthetic fertilizers, herbicides and pesticides. Optimal pH range for fertilizer/nutrient solution for most plant and turf is 5.5-6.5. Mix solution thoroughly and adjust pH prior to application.