As the title says, I need some help figuring out the chemistry in my pool. short story, Came back from vacation to a messy pool. All was fine when I left. Current readings are PH <6.0, FC 0.5 (after a shock yesterday), TA 18 - 20 (suspect this is the problem) and stabilizer reading close to 0 (I had to use a test strip for this one) (yeah, I know). anyway, not sure what to do with the low TA reading. I am suspecting baking soda. Oh yeah, the pool is an 18' above ground. Currently re-reading pool school.