# Thread: Dry Acid effects in Pool Math

1. ## Dry Acid effects in Pool Math

In Pool Math, I put in 20k gal pool, TA=100. In effects of adding chemicals section, I put in 128 oz of dry Acid. The result is pH lowers by 1.07. This seems too small compared to real life. Is the calculation wrong?

2. ## Re: Dry Acid effects in Pool Math

It is an approximation and can be fairly far off sometimes. The effects of adding chemicals section uses a rather approximate method to calculate PH changes. The PH section uses a much better approach and is usually within +-10%. But the effects of adding chemicals section can sometimes be off by far more.

3. ## Re: Dry Acid effects in Pool Math

The calculation is actually dropping too much. In a 20,000 gallon pool with a TA of 100 ppm, adding 128 ounces weight of dry acid would lower the pH from 7.5 to 6.8 so the pH actually drops by 0.66. PoolMath thinks the pH goes down to 6.94 in the upper section to get to 128 ounces weight of dry acid so as Jason notes that's more accurate.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•