Easy-to-use. Add 50ml of MediFin to every 1150 litres (250 gallons) of pond water. Disease recovery can be advanced by using Tetra Pond AquaSafe in conjunction with MediFin. Treatment may be repeated after 7 to 10 days, if recovery is not complete, according to the instructions. MediFin can also be used as a preventative remedy, during sensitive times of the year such as the spring and autumn. Do not use MediFin in conjunction with other pond treatments, except those in the Tetra Pond range. Always read the instructions carefully before use