Hey, I've had my fly river for 2.5 years now and have not once had any health problems or fungus or anything. I started him out in a 23 long tank with silica sand as a substrate against many indivuals reccomendations. For a filter, I used a fulval 204 and had a heater running with the temp around 83 degrees. As for decorations, I use driftwood and artificial plants and had half of a flower pot for a hide. He's since been upgraded to a 65 gallon tall tank with a similar setup only I'm using a rena filstar XP3 on the tank. I use sera aqutan as my water conditioner or stress coat by hagen. I very rarely do a water change but will clean the filter when I notice the water pressure slows down. The filter keeps the water crystal clear and as I said, I've never even seen a scratch on my turtles shell from the sand or any of the decor. The only thing I'm not sure of is my pH level in the tank.
Matt