Swordtail

Question
I wonder if you could give some advice.  I have a tropical aquarium with approximately 17 fish.  I noticed this evening that my swordtail has developed a cloudy slightly bulging eye.  His tail is also looking a little bedraggled.  I am new to keeping fish so could you help.

I have a 45ltr tank with 1 swordtail, 1 siamese fighting fish, 1 golden sucking loach, 8 neon tetras, 4 glowlights, 3 lemon tetras and 2 platies.  I have tested my water and the Ammonia level is 0.25 and the Nitite level is 0.00.  I feed them twice daily with aquarium flakes tropical fish food.

Answer
Hi  Nicole,
This is quite a lot of fish for a 12 gallon tank.  It's a little overstocked, so do you water changes every week of 25%, and try to get your ammonia level down to zero.  The slightest trace of ammonia, can do harm to fish.  It is better to have less fish, and a healthy environment.
Your swordtail has Popeye, along with Fin Rot.  Popeye is usually caused by poor water conditions, injury, and lack of vitamin A.  He also has fin rot which is also caused by poor water conditions.  You will have to treat him with Maracyn, and Maracyn-two combined.
Vary their food so that they get all the vitamins they need.  Good quality flakes are good, but they should also have daphnia, spirulina flakes, bloodworms, plankton flakes, frozen brine shrimp, and glassworms, or mealworms.  The more you vary, the healthier they will be.  The main causes for disease is lack of vitamins, overfeeding, and water quality.  When fish are well fed, they get all the vitamins they need, and with clean water free of ammonia, they never get sick.  It is better to feed them well, keep your water clean, than to have to buy medication which is expensive in the long run.
I hope your little swordtail pulls through.
Lynda