Its been a while since I've been around, the work/school/family groove is running the show these days ... I like what y'all have done with the place. When I get a respite I need to have a look around. To refresh memories on my personal facts, I have five "red hook" silver dollars in a 46 gallon tank with a handful of cories to liven up the place. The youngest of the silver dollars is 4 years old, the eldest is 6. The tank has been remarkable stable for months (pH of 6.5, nitrates in the teens & twenties, 0 ammonia/nitrite issues, but admittedly I ran out of the stuff I was using to monitor water hardness so I'm out of touch with gH and kH), despite the fact that I am only getting in a 30% water change every other week (as opposed to weekly, which I managed to do religiously up until this most recent semester when things got out of hand). It looks like one of my fish has developed a tumor right in front of the anal fin on the bottom. I am attaching a picture. Ignore the yellowish spot, that's just a trick of the light. As you may be able to see, everything else looks good on this guy and his compatriots - eyes are clear, scales are pretty and shiny (minus the humeral spots which I've long since ignored since they've been around for some years now). From what I can tell this isn't "leaking" or a pustule, but I'm asking - has anyone seen something like this? I'd be bummed to lose a fish, but if this is going to get infectious, I'd rather sacrifice one than watch it take over and infect them all. I'd appreciate any thoughts. Maybe if I don't hear from anyone I'll repost this at a different level of the forum.