Hey everyone. I have been lurking around the forums here for a few weeks and decided to finally join up today because i want to continue and learn more about the hobby. I have kept reptiles (snakes mostly) for about a decade and i have always been fascinated by aquariums and fishkeeping in general. The bigger the better of course but i have never really had the room and was hesitant to spend the money as getting into the hobby can be a substantial expense. Well fast forward to a few weeks ago. A friend of mine asks if i want his aquarium. Wife says its loud, pain in the butt to clean and they want it gone. It is a 75gallon with two filters and pretty much everything so of course i took it and i gave his blood parrot to a friend of mine who had an established tank. I poured myself into research including tons from this site and i settled on a single oscar. I spent a month cycling my new tank. Waited patiently. bought a 2" tiger oscar. Waited for him to get settled in which he did. He started eating for two days, became quite comfortable greeting me at the lid for some food. Then after about 4 days of having him his health tapered off dramatically. I kept the lights off for him and he was lethargic and moping around which i have read can happen for short periods. Well he did not get better and i noticed a 2" (size of him) white, stringy bowel movement hanging from him. Initial research said internal parasites. I decided to give it another day. The next day he lost his stringy waste hanging from him but was still lying around. The next day he had an even longer stringy white thing hanging that was longer than him and he was miserable. Gills exhaling rapidly. lying around in corners sick. When he did move he was swimming upside down and all over. Long story short he passed on. I feel bad for not rushing out and treating him with whatever i could right away but it happened quite quickly. I have read alot of posts where people will give contradicting advice (go dump this in the tank or dump that). Anyway I am discouraged and this has been a horrible first experience with fish keeping but i am determined to learn more and in the future i hope i could treat something like this effectively. One question. If indeed it was an internal parasite of sorts. do you believe it likely came from my lfs? i know it is difficult to say for sure but i have no other fish and i have no idea where the disease could have come from. My biological filter seems very strong with no ammonia or nitrites and my nitrates were super low. PH was a little high around 8.2 but stable and i have read that oscars can adapt and that i should not attempt to alter ph. temps were around 78 and stable. Anyway. Thank you for reading my long rant and i look forward to learning and posting here in the future.