TA and PH rise with dichlor/bleach

[Bigralphy]

I have been experiencing ta and pH rise using this method  I have 50 ppm borates and 30 cya.  For the first month my ta was around 50 to 60 and pH was solid at 7.8 .  In the last couple of weeks my ta has been increasing to 80 and pH to 8.0.

Is there a way to slow this down and why would it change after the first month went well?

[chem geek]

There's a small amount of excess lye in bleach that could contribute to a small rise in TA, but it may also be evaporation and refill with tap water since that adds everything that is in the tap water to the spa (e.g. TA and CH).

Adding acid to have the pH lower should lower the TA as well.  If you want to lower the TA faster, then lower the pH to around 7.0 and aerate the water and add more acid to keep the pH down.  Every addition of acid will lower the TA.

[Bigralphy]

Thanks chem geek, I just wasn't sure if this is normal as I will probably need to add acid weekly to keep the ta at 50.