How low can TA be

[chem geek]

So long as you don't use acidic sources of chlorine, like Trichlor (or even Dichlor) and you don't use a regular non-chlorine shock (monopersulfate) which is also acidic, then a very low TA is no problem. You could even go as low as 50 ppm. You just have to compensate (in a plaster/gunite pool or a pool with a tile line with grout) by maintaining a higher CH, pH or combination of the two.

When your pH is 7.5 and your TA is 60, do not add baking soda. Leave the TA alone where it is. With a CYA of 30 ppm (that I'm guessing you have), then you can just have your target pH be at 7.7 and you will be in perfect water balance, though having it at 7.5 is just fine as well (at 7.7, there will be even LESS of a tendency of it to rise further and you'll need less acid to keep it there).

The bottom line is that a TA of 60 is perfectly fine for your pool.

Richard

[dawndenise]

Thanks for the info. Good to know that 50-60 is not too low. I'd like to post a full set of numbers and get your feedback but I don't want to hijack Carl's thread so will post a new thread.