Assuming your result of CC=1.3 is correct, (I not sure about that)
I would suggest you put in 6 large jugs of 6% Clorox (8.52 gallons) the evening before you leave town.

That will shock your pool correctly and you may be able to avoid an algae bloom. If you do not, I can almost promise you will have ZERO chlorine when you get back and perhaps some green water to go with it.

Post new test results when you get back and tell us what your water looks like...lot's of folks here will help you get everything back in line.