Plaster is like Sandpaper

[Mikes Pool]

Quote Originally Posted by chem geek

You've been adding too much baking soda. Have your TA be lower at 70 ppm.

*My TA was around 60 so that is why I added baking soda. Low TA and aeration is what caused erosion of my plaster so I am worried about that and was shooting for a mid-range level.

Also consider using 50 ppm Borates.

*What are the Borates for, to lower my TA?

Only add acid to get to around 7.5 pH (not below) and let the pH get to 7.8 or so before adding acid.

*My pH generally goes from 7.6 to 8.0 overnight.

Also, if you have a short pipe run between your SWCG and the pool, point that return more downwards to help dissolve chlorine gas bubbles because if they outgas that will have the pH rise. The hydrogen gas bubbles from the SWCG also aerate the water which increases carbon dioxide outgassing that raises the pH. Having a lower TA target and higher pH target helps reduce that problem.

*I do have short pipe runs. The returns are aimed so that it barely ripples the surface of the water. What is the correct way to aim the returns? Should I aim all 5 of them down?

Thank you again for your time and expertise.

p.s. I apologize for the structure of this reply. I haven't figured out the tools.

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