Growth Technology have been making nutrient solutions since 1985. The Focus range uses their single-part technology, so there is nothing to mix and match: every Focus product carries the complete profile of all twelve essential minerals, calcium included, which most liquid fertilisers leave out. pH buffered, so it needs no adjustment with most tap water, and free of chlorides, urea and sodium. Odourless.Flower Focus is weighted toward budding and flowering rather than leaf growth.Suits plants in soil, passive hydro and semi-hydro. Use at every watering for best results, increasing the dilution rate as the plant matures. If you are not letting water run through, flush with plain water once a month to stop mineral salts building up. Store cool and dark. No need to refrigerate.