Aquarium plants need a regular supply of nutrients for strong, healthy growth. Aquaria are usually fertilised on a weekly schedule, which means that larger quantities of fertiliser are added at regular intervals.With a Dosator, your aquarium plants are fertilised as in nature, in that they are given a small quantity of nutrients on an ongoing basis. The advantages at a glance: Continuous, consistent supply of nutrients like in nature Consistent, balanced plant growth Prevents algae formation by reducing the level of nutrients Optimum fertilisation in the simplest way Safe operation as there are no moving parts and it uses no electricity (unlike dosing pump) Considerably better value for money than a dosing pump Made from high-quality, durable plastic Designed and made in Germany The Dosator is specially designed for the Dennerle fertilisers V30 Complete and S7 VitaMix.V30 is dispensed automatically over 4 weeks; S7 over the space of 1 week.