Sera Plant Care Set is the ideal CO2 fertilization for aquariums between 15 and 55 gallons. The kit consists of: sera CO2 diffusion reactor sera CO2-Tabs plus (20 tablets) sera florena 100 ml (3.38 fl.oz.) – liquid plant fertilizer with iron, minerals and trace elements sera florenette 24 tablets – iron and mineral fertilizer tablets sera guide "Systemic plant care".
Rivers to Reef says: We have had customers use these with great success even in tanks larger than 55 gallons (we have had several customers with 75 gallon tanks say they noticed a difference in their plant growth and health). Please follow the instructions carefully as you might waste CO2 otherwise.