Ecogrow Powdered Rockwool Nutrients
Rockwool became a popular growing medium in 80's and continues to be so. It is sterile, inert and moisture retentive. Eco introduced the "R" formulas in the late 1980's to fulfill the exacting requirements for plants growing hydroponically in this growing medium.
Ecogrow "R" (14-6-17) is a proven nutrient based, in part, on the Ecogrow "S" formula but with substantial differences. Because it is highly concentrated, it is sold as a two-part formula to prevent adverse chemical reactions. Rockwool has a basic tendency to drift alkaline (pH above 7), which is why we designed the "R" formulas to be slightly more acid than the other Ecogrow powder formulas.