Problems with new set up HELP PLS

[dyereefer]

My brother set up a neww 72 gall bow frt he put baby chromis in to cycle tank twice both times the fish died within 2 hrs he aclimated fish for 1 hrs
before intro to the tank any ideas PH is 8.0 salinity is 1.226
Kh appears to be off the scale I will go double check myself tomorrow
because he is a newb and may have done the test wrong.That is the Kh test.