Help - broken thermometer!

[blissful_sky]

I have baby Kenyi cichlids in a 10 gallon tank at the moment. Though all of a sudden one by one they started to die, so I tested the water and everything was fine. Then did a 25% change and still they died even faster.
So I went to take a very close look at things and found out the floating thermometer was cracked! All along the bottom where the tiny (metal?) black balls are. Then did a VERY large water change and added lots of salt and cleared everything out of the tank.
They do look a better though is there anything I can do? They all seem to die with a bloated belly? As if (sorry for the visual) someone pumped air in them.
I am very worried since I do love my fish very much.

Thanks

 

[ROSS]

mercury poisioning is not responsible. IMO, being that it's no longer found in thermometer's as of a few year's ago but if it's older maybe.

they (your fish) must have swolloed the little lead ball's . as to explain the swollen belly , thus surcoming to lead piosioning. but this is only my opinion as for I have not seen picture's of the fish ... sorry about your fish