Thanks Roger L. for your response.

I have added 4 airlines to the system today. I had it laying around from the time I brought the fish home. I did another ph test and it was exactly the same at 7.6. I will test it again right before bedtime and just before sunup tomorrow.

I thought about the DO, but when the hose was filling the tank, it was just spraying a hard fine mist on top of the water, as I figure if I do it the way, it would add to the DO.

I have slowed down the feeding before the dieoffs, as the temps were getting cooler and the tilapia quit eating good. Now I only occasionally add some rolled oats, maybe every other day.

I used a flashlight tonight and I have 1 female breeder and one 3" baby left in the sumptank. The fishtank is too deep to see any babies, but the larger fish are still hanging in there.