damn fish keep dying!

[digitalsteve]

most of my test kits i believe are pretty accurate , i acclimate my fish for several hrs , so it isnt that , they seem fine during the acclimation, but when they enter the big system they just k.o.. all my other params seem to be fine , other then a little high in the ph. is there an oxygen deficency issue here , the water temp is at 80.2. i know my ammonia is at zero as i have checked it with 3 diffent test kits. is there a way to introduce oxygen into the tank?