Colombo Morenicol Lernex Pro has been developed to tackle the most resistant of worms to keep your fish safe and healthy. This treatment performs best when the water temperature is above 10°C. It is best to test the water first to ensure that quality level is good before using this treatment. The recommended dosage is 1ml for every 20 litres of pond water. If an additional treatment is required this should be added at least 14 days after the first.