Seachem Flourish TABS 10 tab pack. Are growth stimulating tablets for plant roots. They contain essential trace elements, amino acids and vitamins. They are rich in iron , manganese, magnesium, calcium, potassium, chorine, vitamin B12, biotin, and other factors determined to be to essential to plant roots. They contain no phosphate or nitrate which would promote algae prolification. Each pack of ten tablets treats a 30 x 75cm (12' x 30') plant bed twice