adjusting ph and ta

[aiannar974]

I may be getting ahead of myself since my pool is just starting but I do not understand this relationship too well. I am planning a plaster pool with a SWG. I know the ph will tend to raise with the swg and any water features and that I need to bring it down with muriatic acid. However, doesn't this change the TA and put you into a continual spin raising and lowing ph with chemicals that buffer differently?

Anthony

 

[jblizzle]

The acid will lower the pH and TA, but you may reach an equilibrium where the pH does not rise as fast when the TA is low enough. Also your fill water may continually raise the TA to counter the lowering due to acid addition. All speculation at this point.

 

[JasonLion]

It is easy to make large changes in PH without affecting the TA all that much, and it is also possible to dramatically raise the TA without affecting the PH all that much. So in almost all cases you can simply make the adjustment you are trying to make and be done with it, ignoring the very small change in the other number you were not trying to change.

When lowering TA, you lower PH with acid, which also lowers TA. And then raise PH with aeration, which does not affect TA at all. After an appropriate number of cycles you end up where you want to be, though it can sometimes take a while.