2HR Aquarist APT Sky is a specially developed water conditioner for the targeted increase of total hardness (GH) in aquariums, especially for osmosis water. It solves the common problem of how to increase the water hardness without affecting the nutrient ratios (NPK) or the carbonate hardness (KH). 2HR Aquarist APT S/Sky Water Booster allows shrimps and hard water plants to thrive together with soft water plants. APT S/Sky replenishes all essential minerals in osmosis water without negatively affecting NPK, KH or pH.Many conventional GH boosters also affect the carbonate hardness (KH) or the nutrient values (NPK) in addition to the water hardness, which can disrupt the nutrient uptake of plants. APT Sky was developed to specifically increase the total hardness without changing the sensitive balance of fertilisers or the water parameters that are beneficial for aquatic plants.2HR Aquarist APT S/Sky Water Booster+ specifically increases the total hardness (GH) - adds essential minerals s