App and Old Pool Math Not Matching

[brthoren]

I used to use the pool math webpage and switched over to the app about 2yrs ago and have never had any issues. I recently opened my pool and am getting drastically different readings on addition of muriatic acid to lower Ph level. My Ph is at 7.7 and want to lower it to 7.3 and the app is telling me to add 3.3oz of 31.45% muriatic acid while the pool math website is telling me to add 20oz. From past experience I know adding 3.3oz is wrong and the 20oz seems much more accurate. I have entered the TA as well as I know that affects the output. Am I doing something wrong or is there an issue with the app?

 

[ManiacalMama]

I've seen that it varies just slightly, but not by that much. Are you sure you have your pool volume set up correctly?
If I set it at a pool volume of 1600 gal it shows about 3 oz.
If I set it at a volume of 16000 gal it's closer to 30 oz.

 

[proavia]

Sounds like something on your end isn't set up correctly. Check that pool volume and all other settings match in APP and old PoolMath webpage.

Also, since every pool has some salt in it, the APP assumes a salt level of 1000 ppm if you don't enter a salt number. The old PoolMath webpage does not do that.

 

[mknauss]

Share your Poolmath data if you would Helps us help you.
TA is needed as a data point for calculating how much acid to add to effect a pH change. Be sure you have a TA value entered.