I started stocking my tank a little over 2 weeks ago. I started with 6 Yellow tail Acei, 6 Cherry Red Zebras and 6 Saulosi. The problem is I have lost 3 of the saulosi in this time. All of the other fish are doing great. My tank is a 210 gallon with a sump filter. It just seams to be the Saulosi with the problem. They slowly get lethargic and quit eating?