Refill test K JBL Pro Aquatest

Potassium is one of the macroelements that plants in fresh water take effectively within a few hours. During growth, potassium requirements are greater than other elements. While fertilizing regularly, potassium can then go down to a minimum and plants can stagnate in growth.

Potassium deficiency first makes the edges of the chlorotic leaves, which then become necrotic. The leaves twist or roll. In the tap water of central Europe, compared to natural biotopes, potassium is present in reduced quantities, especially in relation to calcium and magnesium concentration. For a good growth of plants the concentration of potassium should be around 10 mg/l; in aquariums with strong lighting (e.g. aquascaping aquariums) we recommend quantities up to 30 mg/l. Higher values in aquarium water promote the growth of filiform green algae. In marine water, potassium is present in a concentration of about 380–400 ml/l, but is consumed only in small quantities

Too high potassium content can become dangerous for sensitive animals such as shrimps. At first, the potassium content of aquarium water should be measured daily. This allows to detect the needs of plants and to dose the fertilizer accordingly. Regular measurements can then be made in longer periods.

Recommended potassium levels

Freshwater aquarium: 10-30 mg/l

Tanganyika-Malawi aquarium: 10-30 mg/l

Vegetable aquariums with few fishes: 10-30 mg/l

Seawater aquarium: potassium content cannot be measured with this test