well im not sure what killed them but it happened within 3 days, all seven fish dead. thought it was ick by the simptoms , except no white spots they started to stress so i did a 25 gallon water change (72 gallon tank) and added copper safe and gave them a fresh water bath, niether worked , they still died. but here is a bit of new info, 2 days after i spotted thousands of tiny little white things swiming around, so tiny i couldnt even see any features , look like little white lines,, is that what killed them? i dont know , please help ,, i want to start up this tank agian
( oh ya after testing the water every thing was normal except amonia was up slightly but not enough to stress them )