Shake well before use. The treatment cycle for Tetra Medica GeneralTonic Plus lasts for eight days. During treatment, please ensure that the aquarium is well aerated. Switch off any UV clarifiers and ozone systems. Do not use activated carbon or any other absorbent filter media to filter the water. Wherever possible, please clean the filter properly before use. Do not remove any fish during treatment to prevent healthy fish from subsequently becoming infected by free-floating pathogens. Dispense Tetra Medica GeneralTonic Plus evenly into the aquarium in the amounts as stipulated below: Day 1: 30 drops (1.5 ml) per 100 l of aquarium water. You are advised not to feed the fish. Day 2: 15 drops (0.75 ml) per 100 l of aquarium water. You are advised not to feed the fish. Days 3 to 6: No application. Feed as normal. Day 7: 30 drops (1.5 ml) per 100 l of aquarium water. You are advised not to feed the fish. Day 8: No application. Feed as normal. Carry out a partial water change (30-50%). After the partial water change we recommend you to use activated carbon to filter the water. If no clear improvement is seen, repeat treatment is recommended after about 2 weeks. Water discolouration is due to the active substance and will disappear after a few days.