NT Labs GH Minerals Up provides minerals for growth, metabolism and other cellular processes which helps maintain healthy conditions for a perfect pond. General hardness minerals such as calcium and magnesium are essential for aquatic biological functions. Such minerals are used in fish growth, metabolism and other physiological functions. General hardness minerals can decrease over time due to influx of rainwater, soft tap water and biological processes using these minerals. NT Labs GH Minerals Up safely increases the GH providing an optimal habitat for your fish and other pond life. NT Labs Koi Care GH Minerals Up Dosage Rate: NT Labs Koi Care GH Minerals Up 1.5kg treats 10200 litres (2250 gallons) NT Labs Koi Care GH Minerals Up 5kg treats 34000 litres (7500 gallons)