Pool store test vs TF-100 why differenent for CH

[blebob]

Pool is fairly new, Water Clear

readings:
FC 3 Pool Store 3
CC 0.0
TC 3
PH 7.8 Pool Store 7.8
T/A 140 Pool Store 120
CH 390 Pool Store 190
CYA 80 Pool Store 100
Salt 3680 Pool Store 3800
Temp 81

after test added 42oz 34% MA

Why would there testing differ?
I did notice that they do not cap there reagents they sit in a box with lids off all day?

 

[JasonLion]

Pool store tests are often surprisingly unreliable. You are actually doing really well, because all the numbers are within the error of the test except CH. Many pool stores are much worse than that.

The CH and CYA tests can be particularly problematic because it takes some time to do them correctly. Pool stores don't generally want to take that much time, so they rush the test and get incorrect results.

I would trust your test results over the pool store.

 

[TizMe]

They leave the caps off because if your doing test after test after test its a pain to put on take off all the time. For your CYA level your min FC level should be 6 and your target FC level should be 9 so you need to raise that some.

House keeping note: Please add your pool info to your to help us help you.

 

[Butterfly]

Hi blebob and welcome to the forum

You did a very nice job on your sig! :-D And, as Jason said, always trust your numbers over a pool store.

For your CYA level your min FC level should be 6 and your target FC level should be 9 so you need to raise that some.

Tiz, he has a SWG and his recommended FC levels are 3 to 5.

 

[TizMe]

Ooops !! I missed that .... sorry !