Erratic Alkaline reading

[luvpizzasj]

Hi everyone,

I am seeing abnormal alkaline reading from day to day. It is baffling me.
I use the AquaCheck Trutest test strips which provides the electronic
reading below.

Chlorine PH Alk Date / Time
----------------------------------------------
9.9 7.5 110 6/25 - 7:38PM
9.9 7.6 170 6/27 - 7:44AM
4.7 7.5 90 6/28 - 8:08AM
2.1 7.4 170 6/29 - 8:00AM
0 7.6 100 7/3 - 8:10AM
0 7.5 180 7/5 - 7:27PM
Add 1gallon Kemtelk liquid chlorine
2 7.3 150 7/7 8:10PM
5.2 7.4 200 7/8 9:46PM

I don't understand why the Alkaline number jump all over the place.
My pool is about 40'x25' with 20K+ gallon of water.

Can someone give me a feedback? Maybe this electronic AquaCheck
reader is not reliable?

Thank you in advance for information and help.

Jeff

[Denniswiseman]

I had the AquaCheck and dumped it for a FAS/DPD kit
They use dip strips which aren't reliable
You really need to get yourself a decent FAS/DPD test kit (Taylor K2006c or TF Testkits TF100 in the states)
They test for free chlorine and total chlorine and CYA as well

[Teapot1]

Take an innacurate dip strip and put it in an electronic reader and you still have an innacurate method of testing because dip strips are innacurate.
Sell it on and buy something better is my advice. Dennis has made a good suggestion.