Each Gromin plant nutrient tablet pack has been formulated for one full reservoir. Each time you refill the reservoir with 60 litres of pure drinking water, you will have to add the five tablets that is provided in a pack. Throughly dissolve the five tablets from the pack in a clean container of lukewarm water. Add this mix to the reservoir along with the 60 litres of pure drinking water. Do not add more or less than the recommended dosage. This will lead to plant stress and effect its growth.