cichlid possibly sick?

Question
Hello, just checking on a few questions on electric yellow cichlid and came to notice your site. The problem im having right now is with one of my three yellow cichlids. The electric yellow in question seems to be bloted around the mouth.Now the cichlid is a male to what i believe. It does have black on the top and anal fins. The fish is not eating but is still coming out for food. He is the back facing up behind a fake log. I have to metion a couple of weeks ago I had a problem with my my nitrate, nitrite, and ammnoia levels being too high. This was because i cleaned my filter wrong, and use tap water. I did lose two fish to nitrite poisioning. To fix this, I did 20% water changes daily, also adding chemicals (prime and Stablity).  The tank is a 90 Gallon tank with about 24 mawai cichlids with one peco. I use a marianland c360 canister filter. My levels do seem a bit high but I did do 30% water change yesterday. The eltric yellow still comes out and does not stay to one spot, so i do not believe its nitrate poisioning again. There is no red showing as for blood and he isn't sitting near the top or right at the bottom. Could this be aggerision or something else? Its been two days without eating and I would like to get him eating again so I do not lose him. Thank you for your time

Answer
Hi Chris,
I would think that he has Swim Bladder Disease.  This disease is caused by constipation.  This happens by poor diet, and overfeeding.  If left untreated it will lead to dropsy.  Feeding fish cooked frozen peas with the outer layer removed once a week, prevents this disease.  On the day you feed your fish peas, feed them nothing else for the rest of the day so they can clean out their system, and avoid this disease.  
Vary their diet, Spirulina, a good quality flake, presoaked pellets for African Cichlids, bloodworms now, and then, are very good for your fish.  They need variation to get all the vitamins they need.  The more you vary, the healthier they will be.  Good food, and clean water go a long way in preventing disease.  When feeding your fish, feed them 2-3 times a day in small amounts.  3 small meals are better than one big meal.  We must always remember that they have tiny tummys when feeding them.
Seeing as you little yellow electric will not eat, I would treat him with Kanamycin, or Tetracycline.  Hopefully you have a hospital tank for him.  This disease is not catching, and I would hate for you to have to treat a 90 gallon tank!  It would be worth the money to buy a hospital tank of at least 5 or 10 gallons.
Remove 5-10 gallons of water from you 90 gallon tank.  Buy a used sponge for your hospital tank, and remove the carbon.  A used sponge will continue to bring good bacteria to your hospital tank.  Follow the directions on the package.  Do not use salt.  
I hope the little guy pulls through.
Lynda