Linz got me an aquarium for my birthday, and so the adventure began. After a 20+ year hiatus, I was once again fish-crazy. And I made a new discovery - cycling. Back in "the old days" the books I had never mentioned cycling. No one talked about "New Tank Syndrome". It made sense to me - after all, I'm an ecologist, I am aware of the nitrogen cycle. But it still seemed an awful imposition :)
Anyway, with a 55-gallon tank and "magic" bacterial cultures to add, I figured I could cheat a bit. So I added plants, figuring they would help things along, and Linz's fighter. And after a couple days I bought a few platies. That's where the problem started - everything I read said more females than males, so I asked for 3 females and two males. I figured that the guy at the pet store should know what he was up to, but once I got them home and had a look at them I realised that I had four males and one female. So a few days later, since she was being harrassed so much, I added four more females. And, of course, some Corys.
A few days later, after the first female had given birth, I noticed fin rot on her and one other the other females. Not sure what that meant, I moved them into the old fighter tank, where they promptly died. (The fighter had also expired the previous day - I felt really badly, since he wasn't mine). Only then did I got looking online, and realise that rather than being a contagious disease, fin rot was most likely to be a symptom of bad water quality. So I did a water change - about 10%, because I didn't want to mess up the cycling too much.
The next day I noticed that the remaining females in the tank didn't look well either, and had some fin rot. I was going to attribute it to (harrassment by the males, but then I noticed "shimmying", and I remembered seeing something about it on a disease page. So I looked into it, and realised that my water temperature was set really low. I raised it any everyone seemed happy.