Joey - I think increased deaths on April 18 are normal and due to starvation of those not eating. Your total death count when plottted on a graph will have somewhat of a bell shaped curve. Fish death rate currently is probably in the high part of be curve. As long as you are regularly making water changes your water quality should remain okay. The main thing to moitor for is ammonia. Are you making any tests for ammonia? If you are making regular water changes, I don't think they would be needed based on your set up and the size & number of fish.
