Humble, Mel, Brew, have any of you ever used this? I guess not as it is a German company and never heard anything about it in US forums. This is the composition: Recommendation is to dose 60ml per 100l (start with 40, than add another 20 two days later). So I guess we are dosing 120mg of copper sulphate pentahydrate per 100 liters. Any idea what concentration this implies? They also say that the treatment (since first 40ml dose) only lasts 7 days, which does not make a lot of sense given ich lifecycle (unless the initial dose already brings concentration to therapeautical level, or the combination with Malachite green is especially effective).