New house with pool

PoolStored said:

You may find your pH is 7.0 after baking soda, which is fine. It will rise over time. I left a bit of room so you can use some washing soda after baking sod if you want to raise pH.

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Sodium bicarbonate has a ph of about 8.0. How will it lower his ph?

Ibelyle said:

Sodium bicarbonate has a ph of about 8.0. How will it lower his ph?

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His pH was 6.8 at the time and his TA was 20. The sodium bicarb was to raise TA. In the volume I quoted, it would likely raise his pH by .1. It is also possible, given test error, that the sodium bicarb would raise it to 7.0. THAT is why I said what I said. I quoted an amount of bicarb that would get him to the low end of acceptable TA, so that if the pH was still in the 6s, he could add a bit of washing soda to finish the TA and pH increase.

Ibelyle said:

A drop of thiosulfate before adding the reagent will avoid any interference with the test. Meanwhile a high ph (8.0) will greatly reduce the effectiveness of chlorine.

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Taylor uses a proprietary blend of chlorine neutralizers that try to net out/to not change the pH when chlorine is present. The sodium thiosulfate in the R-0007, however, tends to be of high pH and will not react with chlorine in a pH neutral way so will affect the pH test which is why Taylor recommends not to use it. With CYA in the water, the pH test may still be OK for a short time even with FC between 10 and 15 ppm, but for simplicity and to be conservative we generally say not to consider the pH test to be valid when the FC is higher than 10 ppm. (Hint: Trouble Free)

You can't win with sodium thiosulfate and the PH test. Adding enough to have any meaningful effect on the FC level will throw off the PH reading. If you absolutely must have PH readings when FC levels are high, you will need a completely different approach.

jtrhodes81 said:

I know granulated CYA is cheaper than the liquid, but has anyone had an issue with the liquid stuff not raising the CYA? I tested before and a few days after adding a gallon of stabilizer, added no water and had no change in the CYA level. The liquid CYA was from a reputable pool store so I wouldn't have thought I was getting a fake product.

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Never heard of this either. I'd guess more likely your CYA test is bad. @JoyfulNoise any thoughts?

Chris

jtrhodes81 said:

I know granulated CYA is cheaper than the liquid, but has anyone had an issue with the liquid stuff not raising the CYA? I tested before and a few days after adding a gallon of stabilizer, added no water and had no change in the CYA level. The liquid CYA was from a reputable pool store so I wouldn't have thought I was getting a fake product.

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Did you rinse out the bottom of the jug? In liquid a lot of the CYA is settled in a slurry at the bottom.