Which test to believe?

[tanikir]

I am using a Walmart HTH brand test kit until my TF-1000 arrives. I took a sample to the pool store last week for a more accurate reading, but the difference seems to be to much. I wanted to add borates, but now I don't know if my TA is in line.

Pool Store said last week:
TC 1.3
FC 1.3
PH 7.4
TA 75
TH 330
CYA 61

Walmart test says today:
FC 1
PH 7.8
TA 90-100
CH 410
CYA <30 (the drop disappeared just a few drops above the 30 line, the top of the bottle)

Do I need to lower the TA more before borates?
Is the CH too high? I don't want to replace the water after the borates. (I have a vinyl liner)
How much chlorine do I use? Thats a big spread for the CYA.

 

[Guest]

How is the pool store testing? Their 75 ppm for CYA suggests either strips or reagent vials being read by a photometer or colorimeter. For TA and CYA these tests are not necessarily better or more precise than the one in your kit! (I won't bore you with the technical reasons.)

 

[tanikir]

I don't know what the pool store used for each test. They have Bioguards Alex software and a combination of a wet lab and strip reader. I'm not sure what tests were done with the lab and what was done with the reader.

It sound's like I should go ahead and up the CYA?

Is my CH too high? I'm not sure if I should worry or not. We do have hard water in this area, but I'm sure a big part of it is all the cal-hypo I used last year.

 

[JasonLion]

Test strips, even when read by an electronic strip reader, can be amazingly inaccurate. I would trust the WalMart kit over test strips every time.

 

[frustratedpoolmom]

It sound's like I should go ahead and up the CYA?

Is my CH too high? I'm not sure if I should worry or not. We do have hard water in this area, but I'm sure a big part of it is all the cal-hypo I used last year.

CH is high, but you can control problems by keeping your PH at 7.6, and never above 7.8. I would assume if your refill water is lower, the number will gradually drop over time thru backwashing.

As for the CYA, I suppose it wouldn't hurt to bump it up 10ppm to 40, until you can test with your TF100. That way if its really higher, you haven't done too much damage and backwashing will slowly drop it anyway. Refer to the CYA chart for your recommended chlorine levels.

 

[Guest]

I don't know what the pool store used for each test. They have Bioguards Alex software and a combination of a wet lab and strip reader. I'm not sure what tests were done with the lab and what was done with the reader.

It sound's like I should go ahead and up the CYA?

Is my CH too high? I'm not sure if I should worry or not. We do have hard water in this area, but I'm sure a big part of it is all the cal-hypo I used last year.

The ALEX system is notorious for inaccurate results. I would not trust it as far as I could throw it. The syetem is designed to sell as many chems as possble for Bioguard dealers! It uses test strips for most of the tests. Trust your HTH kit!

 

[tanikir]

Test strips, even when read by an electronic strip reader, can be amazingly inaccurate. I would trust the WalMart kit over test strips every time.

Maybe that's why they said I shouldn't worry about the CYA until it's over 200!

 

[Guest]

Test strips, even when read by an electronic strip reader, can be amazingly inaccurate. I would trust the WalMart kit over test strips every time.

Maybe that's why they said I shouldn't worry about the CYA until it's over 200!

Actually thaat is the coperate stance for all the Chemtura companies. Chemtura is one of the worlds largest manufacturers of trichlor and dichlor products and their brands include Bioguard, Guardex, Sun, Omni, Pooltime, and Aquachem just to name a few of them. There are many more.
I have actually been told this on the phone by Chemtura techs!

 

[Bob_Funk]

either result with your cya-get your chlorine up