Pool Math and Adding Salt

[Sollace]

Our salt content was low, added salt last night, retested just a bit ago, and these are my numbers:

2600 - Low salt
3000 - After adding 20lbs (half a bag) (half of what pool math said to add)
Wanting to get to the target of 3200

Current salt level is now 3000, target is 3200
Pool math said to put in 21 pounds.
This is off in my book, way too much.

I put in 20lbs of salt to gain 400.
I now want to gain 200 so I put in almost 9lbs or 13 cups of salt. (Still conservative)

I don't know if the calculations on pool math salt are off but I thought I'd mention it.

 

[mknauss]

The K1766 is accurate within 200 ppm. Your testing is not as accurate as you hope.

 

[Sollace]

Yes I am using the K1766 Taylor Salt Test kit.

It's Pool Math and those numbers they suggested. If I added 21 pounds of salt I'd get way over my target. Right? Or is it my poor math?

IE: Re the test kit I am at 3000 salt -- Target is 3200.
Put those numbers in pool math and I'm told to put in 21 pounds more of salt
That's excessive. Right?

 

[mknauss]

Poolmath uses the data you enter.
20 lbs of salt in your pool volume will raise the salinity 189 ppm. Every time.

 

[Sollace]

Okay - Thanks. I'll retest again and see how the new addition goes. I know to take this slow.

 

[Saturn94]

Okay - Thanks. I'll retest again and see how the new addition goes. I know to take this slow.

Is it possible your pool volume is actually smaller than you think? That would cause added salt to go up more than expected. If you’re not sure if Pool Math is giving you a good number, you can always add less like you did and “sneak up” on your target level.