The doser has been specifically designed for use with V30 Complete and S7 VitaMix as part of the Dennerle fertilization system. V30 is dosed automatically over 4 weeks, while S7 is dosed over 1 week (2 dosers are needed for this). With the innovative fertilizer doser made of high-quality, durable plastic, aquariums ranging from 50 to 300 liters can be supplied. The doser is also ideal for use with V30 as a standalone fertilizer, providing a consistent, drop-wise fertilizer supply over 1 month. Since the doser operates purely on the physical principle of osmosis and has no moving parts, nor does it require batteries or a power connection, it works very reliably and economically. It also offers significant advantages over a traditional daily fertilizer, as the device only needs to be refilled once a week (for S7) or once a month (for V30).