Regular water changes
Food, plant remains and metabolic products pollute the aquarium water. Because aquarium filters cannot completely remove these substances from the water and a large part of the dirt ends up in the bottom substrate, a partial water change must be carried out regularly (approximately 1/3 of the water content every 2 weeks). The water change must always be connected to the suction of the substrate. After a water change, a good water conditioner, such as JBL Biotopol, must be used to make the new tap water fish-friendly.

Easy installation:
Connect the water jet pump to the water tap. Connect a long hose to the pump and to the mole bell on the other side. Hang mole bell in the aquarium. Place the shut-off valve on the pump in the passage. Open the water tap vigorously. The water flowing past sucks in the aquarium water. Clean the aquarium bottom during the suction process with the molm clock. To refill the aquarium, connect the tap to the pump and allow fresh water to flow into the aquarium.

If the 8 m hose is not sufficient, an extension is available (JBL PROCLEAN AQUA IN-OUT Extension Set).

This is how the aquarium bottom is properly cleaned:
Move the mole clock in the bottom soil of your aquarium with rotating movements. The suction force pulls the substrate and dirt up in the bell. Due to its own weight, the substrate falls back and only the dirt is sucked out of the aquarium. For fine sand you can adjust the suction force by lifting the mole bell so that the light sand also falls down again. A sieve in the bell prevents accidental sucking in of fish and shrimp. The sieve can be removed for cleaning.
If there is a sustainable soil fertilizer under the covering gravel layer (e.g. JBL PROFLORA AQUA BASIS), the mole clock should not be pressed into the substrate all the way to the bottom, but only into the covering soil layer.