Anyone have any problems using melafix. I used the required dose in a 1000 gallon fish only tank and my water became somewhat cloudy and the fish started stressing out. I call the company after three days treatment and they told me that the problem was not from the melafix and that I probably have another problem. I stopped medicating and did some water changes. My tank finally recovered and fish are eating again. I did lose half my fish including some I've have over 15 years. The fish I was treating for did not die.