I have two medium sized parrot cichlids (about 5-6in.) that are housed in a 36 gal. tank they were moved into about two months ago. I have had them for over 4 years now but I am by no means an expert keeper on parrot cichlids so I am looking for some help! While one fish is always healthy (knock on wood), the other seems to get sick quite often. Right now, he/she just stays near the top corner of the tank and appears to be quite lethargic. This fish is also quite large and pale in the belly area and has little to no appetite at all. It's eyes are also a bit yellow.This has happened to the same fish a few times before but after an X number of days snaps right out of it and goes back to its normal self. Each time I think this is the end for this particular fish which makes me quite worried. I have read that it could be bloating or dropsy, but frankly reading around the internet has just gotten me more and more confused. I want some solid advice before really trying anything that could harm the fish even more or do something to the tank. When I bought these guys I had no idea how much harder they were to care for than typical fish, so if there is anyone who might know what is going on any advice is appreciated! I just want my fish to get better because I truly enjoy having them as pets. If any other details are needed please let me know and I will do the best to answer. Thank you in advance for the help!