Ok so I have had my 55 gallon for a little over a year now and just got the 1.5 gallon last week for my fry. Well slowly but surely my fish are dying off in my big tank,my black female molly has some crazy issues. She will swell up huge for a day or 2 and then just go back to normal her color fades in and out and a big bubble comes up on one eye and then will go away but keeps coming back,she swims like shes dying then goes back to normal,this all has been happening with her for some time now. I did tests on my water in both tanks my 55 gallon is as follows....Ammonia 0,Nitrate 80,Nitrite 0,hardness 150,Alkalinity 80 and P.H. 8.4-everything was perfect till my husband put some fizzing tablets in a while back,I don't know if he did the ick clear fiz tabs or the water conditioner,and he doesn't remember,That killed off many of my fry and other fish the next day,I tried doing a major water change but apparently didn't help. As for my fry tank....it is 1.5 gallons and the tests read as follows....Ammonia 8.0 (but was a much darker green than the paper showed),Nitrate 0,Nitrite .5,Hardness 300,Alkalinity 180 and P.H. 8.4! Please help me with what I need to do to fix these before everything dies in my tank. I am desperate I have never had this happen.Thank you for any possible help.