today in my 90g tank I lost 22 fish outa 32 in a matter of 16 hours all my levels are good ph 7 ammonia 0 temp 79.4f ,it is a establish tank of 2 years I did 25% water change every 1-2 weeks never over fed them,first I though they got shocked frm my heater but its working fine,but the 10 that...