Dead Fish...

I would suggest leaving the tank bare for 30 days to quash the cycle of ich.
 
Also, if your water company uses chloramine to treat their water you will have to use an ammonia reducer. The water treatments that only deal with cloramine and chlorine will leave ammonia as a by-product if chloramine is in fact the disinfectant that the water company uses.
 
1) stop adding anymore fish
2) with no fish in the tank, do a 100% water change
3) raise temp to 87F
4) add 3 tablespoon of aquarium salt per gallon of water
5) add some pure ammonia from walmart until your test shows a reading of 2ppm
6) maintain an amonia reading of 2ppm, temp 87F, and the initial 3tablespoon per gallon salt level for the next 4 weeks
7) after 4 weeks, reduce temp to 75F, bring salt level back to 0 through water changes
8) order some fish online (aquabid, petsolutions etc), your LFS are obviously selling you diseased/sick fish.
 
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