I agree with the others, the fact that you have pulled out most of
your stem plants and replaced the two large swords with smaller ones
has probably greatly reduced the amount of oxygen being generated in
the tank. Perhaps you had a hot day or something similar that made
this condition even more stressing. I would increase surface agitation
in general or add an air stone until the plants are producing enough
oxygen again or you have added some fast growing stems or similar
plants. Glad to hear they were better after the water change.

Hope that helps
Giancarlo Podio


"Victor M. Martinez" wrote in message ...
Yesterday one of my mature SAE died. Just now I fished one out of the
tank. The rest are hiding in the large amazon sword. I did notice they
were "breathing" really fast lately, but I didn't think any of it because
all the other fish were acting normally. I just went back to check on them
and 2 of them are very pale, the other two have normal color. I tested the
water and it's all within normal parameters. I have no idea what could be
happening. The only change they've had in the past 4 months was a plant
re-arrangement. I pulled out 2 large swords and replaced them with little
ones, plus I removed most of the stem plants.
Any advise would be most appreciated.

Victor M. Martinez

http://www.che.utexas.edu/~martiv