Hi guys! This is my first time posting here and I'm very nervous for my fish... Here's some info: * Ammonia Level(Tank) 0 * * Nitrite Level(Tank)0 * * Nitrate level(Tank)20 * * Ph Level, Tank (If possible, KH, GH and chloramines) normal range * Other Required Info: * * Brand of test-kit used and whether strips or drops? API test kit * * Tank size (how many gals.) and how long has it been running? 55 gal, 4 years? * * What is the name and "size of the filter"(s)? 1- marineland 2-55/75 aqeuon * * How often do you change the water and how much? Once a week, ~90% * * How many days ago was the last water change and how much did you change? Two days, 90% * * How many fish in the tank and their size? 2 large * * What kind of water additives or conditioners? Prime * * What do you feed your fish and how often? Flakes, once a day * * Any new fish added to the tank? Yes, but it was a fish being quarantined bc he was sick, now I added him back to the main tank * * List entire medication/treatment history for fish and tank.Please include salt, Prazi, PP, etc and the approximate time and duration of treatment. Nothing as of the last 3 years or so * * Any unusual findings on the fish such as "grains of salt," bloody streaks, frayed fins or fungus? Bloody streaks, one red growth on top of head, one really big growth on the side of the body, has been growing for three months, kinda popping out and white (tumor????) * * Any unusual behavior like staying at the bottom, not eating, etc.? Eating very well and always asks for food, but sometimes sitting at the bottom but not often I was gone on vacation for two months and gave him to my friend in a 20 gallon tank (back when the other fish was quarantined), but kept the same filters and he was prompt w the water changes and feeding schedule, but he just noticed the bump growing. The bump looks white on the top. Is it contagious and should I quarantine him?