Unlike other years, pH isn't naturally rising

wayner said:

The only reason that I can think of is that we have had more rain than usual and I have not had to add water - after running the pool with water over the skimmer I actually pumped some water out. Could it be acidic rain decreasing my pH.

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The rain could be acidic and the fill water can also be basic which it usually is. Combined, could mean that PH does not rise as quickly.

Anode 4Cl^- -> 2Cl2.

Cathode 4H2O -> 2H₂ + 4OH^-.

2Cl₂ +2H₂O -> 3H⁺ + HOCl + OCl^- + 2Cl^-

HOCl + OCl^-+ uv light -> O2 + H⁺ + 2Cl^-.

Net reaction:

6H₂O + 4Cl^- --> 4H₂O + 4Cl^- + 2H₂ + O₂.

Following the process, we can see that there are 4H⁺ and 4OH^- created, which nets out to ph neutral.

The chlorine gas generated is very acidic and creates 3 hydrogen ions for every 4 hydroxide ions created.

As the hypochlorous acid is broken down by uv, 1 more hydrogen ion is created for a net neutral result.

Assuming that chlorine gain and loss are equal, there's no ph rise.

For a SWG, you gain and lose the same amount on a continuous basis once you reach equilibrium.