jdhef

There had been a virus going around that was killing DG's, but I'm not sure what the symptoms were, but it is possible that is what killed him.

Sometimes you just get unhealthy fish from the store. The fish we buy have really been through quite a bit by the time they end up in our tanks. I personally had some problems with my Rainbow Fish when I first got set up and running. I bought 3 and about a week later one died for no apparent reason. I then bought a replacement Rainbow, and he was doing great for two weeks. Then on July 4th of last year I checked the tank before going out and all the fish looked fine, happy and healthy. I got home a few hours later and the replacement Rainbow was dead. I replaced that Rainbow with another and they were all doing great for about one year, until that replacement Rainbow developed Gill disease and died.

But two of the origonal Rainbows are doing great after a year and a half. And the latest replacement seems to be doing great...but apparently if my Rainbow Fish were a rock band named Spinal Tap, those Rainbow fish would have been the drummers. (If you haven't seen the movie "This is Spinal Tap" you probably won't get that!)

namehater

i dont think this is your problem, but i personally dont think this is a very good acclimation process. typically when i acclimate a new fish i put all of its water in a bucket along with the fish, then i start a syphon and run that to my bucket with the new fish in it. find a way to slow down the syphon so that its just a little trickle, if your using a gravel vac you can tie the hose in a loose knot, tighten the knot to decrease the flow rate. the slower the trickle off the syphon, then the longer it will take to acclimate the new fish, but also, the longer it takes, the better it is for the fish.

i normally let the syphon drip into the bucket for about 45min. keeping a close eye on the bucket so that it doesnt overflow, when the water level in the bucket starts getting close to the top i use a cup to pull water from the bucket and just dump that down the sink.

ive also used the small tubing for air lines to acclimate, this works better than the syphon, because the small tubing is easier to work with on controlling the syphon flow.

misterblobby

I use an acclimation procedure similar to namehater, but just gradually pour in tank water over about 30 minutes to an hour & then take them out with a net in an attempt to prevent any parasites that might have come from the fish shop going into the tank.

Possibly a stupid question, but do you have carbon in the filter? If so, how old is it? Dissolved organic stuff isn't necessarily going to show up with a test kit but might be killing fish.