Septasemia - sorry for the spelling I know it is wrong but it is about as close as I can come right now.
Basically the gourami bugged the Angel for a long time and finally the Angel had enough... and the gourami got beaten up pretty badly. Then because he was hurt he was more suseptable to infections/etc. I also had a tank full of 'rescue' fish that were in bad shape from lack of tank maintenance (the previous owner did not know what she was doing was wrong - she was following the advice she was given).
They had various problems but I had to get them used to a lower nitrate level before I could start the medications.
I always used a separate set of equipment on my QT tanks to try to prevent cross contaimination. It was a good idea and worked well while I only had one QT tank running. The Gourami and Angel were in one QT and the bunch of 'rescues' were in another QT. I used the same equipment and spread the infections from the rescue fish to my beaten up Gourami.
Septasemia I think is when the blood vessels become weak and break. I first saw the blood on the fins - but he was red in other places from being beaten up.
The Angel was fine - no issues at all but then he was strong and healthy - no injures. I was told that it would affect only weakened fish - either from injuries, other diseases, or bad water parms.
It could be that this 'ghostie' already had the problem when you bought him.
Keep a close eye on the rest - and keep the water the best that you can.
Have they finished working in your area yet? A new complex is being built directly across the street from me. Your message has really got me thinking as it is ony a matter of time before they have to dig up the water pipe to extend it into the new complex. I may just start filling up some larger water bottles that I have ... just in case.
