Thanks all. After I posted I sat and thought about numbers. If 1 gal of bleach adds 5.25ppm to 10K gal and I have 15K (give or take. Even Doughboy can't give me an exact capacity!) then it would take 1.5 gal to get me from a 5 to a 10. It got me where it should've with only a gallon.

I want to turn on the heater because the water's not very warm. Although the days are in the 70's the nights drop down to the low 50s. Without enough CA I can't do that.

How do I increase the CA by using only the BBB method?

Tonight's numbers were:

FC - 9
CC - 0
TC - 9
pH - 7.3? (hard to tell color exactly)
Alk - 100
CA - 160
Cya - 0

I've added 2# of Borax to up the pH and half a gal of bleach tonight. We'll see what it looks like in the AM.

What exactly do color blind people do for pool testing? It's hard for me sometimes to discern the subtle color changes. My son's color blind and couldn't do this to save his soul.

Thanks all.

CoffeeBean