Fluctuating pH

[sehaasch]

I have been testing my chemical levels every day for the past 5 days. My FC started at 18 and has slowly decreased to 9. TA has been a constant 50. My pH has been 7.2. Pool Math tells me to add 1/2 an ounce of Borax, and when I do, the pH goes up to 7.6, but then the TA goes down to 30. When I test it 24 hours later, the pH is down to 7.2 and the TA is 50. MY CH is 350, CYA is less than 30 (the measuring device only went as low as 30) and CC is 1.5. My test kit doesn't test for Borate. If I don't plug that in to pool math, will that throw anything off? Only one person used the spa once during these 5 days for about 30 minutes.


260 gal., cartridge filter, outdoor, well water,

 

[jblizzle]

1. When the FC > 10ppm, then the pH test is not valid.
2. Pool Math does not "tell you" anything. You set the targets. So, IF your pH is 7.2 that is fine and there is no need to raise it since it will likely rise on its own. {Just realized this is a spa, so the pH is certainly going to rise quickly due to all the aeration}
3. Borax will raise the pH and also raise the TA a little it will not lower the TA, must be testing error
4. Large swing in pH and TA that quickly are not possible without adding something to the water. How are you chlorinating? I would not expect the pH to drop like that in a spa.
5. If you have not intentionally added borates (not a little borax for small pH adjustments) then leave it at 0 in PoolMath.

 

[sehaasch]

I'm using Bromine, which has also been testing high. So what should I do first? Lower the FC so I get a more accurate oN reading? How do I do that?

 

[jblizzle]

You wait for the FC to drop. Otherwise you can not get an accurate pH reading.