I have a 110 gallson planted tank with cardinal tetras, bristlenose plecos, clown loaches, 3 pigeon blood discus, 3 red turks and 3 red marlboro's. The tank has been set up just over a year and doing really well. The latest additons were the marlboro reds and I've had them for 4-5 months. I change the water twice a week and each time do a 50% change. The temp. is about 86. I feed a variety including flakes for discus, pellets, frozen brine shrimp and frozen blood worms. So here's my question: One of the marlboro reds have lost the red colour. There's some white patches which kinda look like my pigeon blood. The other day I noticed it and thought it WAS one of the pigeon bloods. The other 2 look the same. Any idea why he lost his colour?