I am treating my tank with Mardel Copper Safe for velvet and Maricyn 2 for secondary infections and my water is very cloudy and I know that is normal but my fish are always pooping a and one has a string of poop about 3 inches long!!! and it is white and is that okay and they seem healthy and they show no signs of stress and the company said that you can use copper safe and maricyn 2 togather and it says that on the box.