dying fish

[plecoperson]

I suspect my tank WAS overstocked and I have 25 molly fry in it at the moment but Im having probs with my fish dying

in the last couple of months ive lost 2 girl mollies (about 3 weeks apart, and 2 weeks after they had babies) a platy and a silvertipped tetra. The platy went very fat before it died - i thought it was pregnant even though I suspected it was male. When i looked at it's dead body, it had a pale area in the abdomen. Perhaps it ate gravel but what are the symptome of bloat? can they die from it. what can I do about all my fish dying? the tak wasnt very clean but I cleaned it yesterday and all water test were normal.

 

[LoveMyOscar]

...

 

[TetraMon]

Hope and pray it's not dropsy. Just in case take all of the fish that are bloating out of that tank and into a spare. Dropsy is some kind of internal bacterial infection, i think, that normaly can't be cured. Symptoms are bloating and scales tend to lift. I had it once with my guppies and didn't take them out in time... they all died.
Good luck

 

[plecoperson]

The deaths seem to be staggered. Silver molly was about 3 weeks ago, silvertip 1 1/2 months platy 2 weeks and molly yesterday.

readings were pH 7.5 Oxygen 5 ammonia 0 nitrate 0 nitrite 0

have the below fish in it and I think its 20g possibly more tank was set up in december last water change was yesterday and changed about 30/40% of the water before that the water change was about 2 or 3 weeks ago. I always dechlorinate.

when they die it seems to me that they go downhill only as much as one day before they die, and most of the time its only one or two hours and i dont really have a spare tank, only an isolation net. the scales dont seem to be lifting, they dont seem to be red patches, gills dont look to be especially inflamed.