TF Testkit question.

[Crimson]

Got my TF test kit. Got some questions on the proper way to use it. First of all, is it OK to add multiple drops when it calls for one drop at a time? What I mean by this is like the test for CH when you know your CH is at least 200, is it OK to add like 15 drops, then mix, and start adding one at a time? Or should you do one at a time and mix between each one even though you will need to add 25-30 drops?

Next question is that i am getting some results for my TA and CH which vary fairly wildly from the pool store tests. In the pool store (Multiple), my TA ranges from about 100-150 depending on the store. When I tested it I got 190.. I added acid and my test dropped to 170. I am thinking I may need to wipe every few drops with a wet cloth?

Also, my CH is MUCH higher with the TF Testkit. Stores say 200-220, my test shows more like 370! Again, maybe I need to wipe off the bottles to make sure drop size is more consisent? Also, see my notes about doing multiple drops above.

Help would be appreciated.

 

[reebok]

you can try the damp cloth trick. I think they say damp tissue though usually. not sure if it matters. my CH reading is 625 and two pool stores told me it was 400. thanks pool stores for my calcium scaling

 

[Guest]

Got my TF test kit. Got some questions on the proper way to use it. First of all, is it OK to add multiple drops when it calls for one drop at a time? What I mean by this is like the test for CH when you know your CH is at least 200, is it OK to add like 15 drops, then mix, and start adding one at a time?
In a word, no.

Or should you do one at a time and mix between each one even though you will need to add 25-30 drops?
yes, and for the CH test you should swirl the vial for 20-30 seconds between drops.

Next question is that i am getting some results for my TA and CH which vary fairly wildly from the pool store tests. In the pool store (Multiple), my TA ranges from about 100-150 depending on the store. When I tested it I got 190.. I added acid and my test dropped to 170. I am thinking I may need to wipe every few drops with a wet cloth?
Try it. Also make sure you hold the bottle completely upside down and let the drop form. Don't squeeze it out.
Also, my CH is MUCH higher with the TF Testkit. Stores say 200-220, my test shows more like 370! Again, maybe I need to wipe off the bottles to make sure drop size is more consisent? Also, see my notes about doing multiple drops above.
You just answered your own question on both points.
Help would be appreciated.

Help has been given.

 

[Crimson]

Thanks, I'll give it a try tomorrow when the wife is at work. She already thinks I am borderline psycho about testing before I got my tf testkit.. now she's really concerned.

 

[duraleigh]

Hey, Crimson,

The static electricity issue (causing the TA test to skew) has not been demonstrated on any reagent other than the R-0009.

In other words, wipe the tips with a damp cloth or paper towel during the TA test but it is not necessary for the CH test. You CH test is likely accurate.

 

[PaulR]

If you eyeball the drops as you're putting them in, you can probably tell if they look "normal" size. Squeeze the bottle gently, let the drop form on the tip and fall off naturally, no spitting/squirting.
--paulr

 

[Crimson]

I re-did each test and I came up with #'s more in line with what the pool store was giving me. CH was 240 and TA was 140. I payed much more attention to the size of the drops and everyone was right you can see when they are a bit too small.

On the chlorine test, how do you get it more accurate? I see people mention its .5 or .2 depending on how you do the test. If you increase the amount of water to 20ml instead of 10 does it become .2? (Or .25?)

 

[DaveNJ]

Alternate methods from Pool School article.
alternate-test-procedures-for-the-tf-test-kit-t1723.html

 

[PaulR]

On the chlorine test, how do you get it more accurate? I see people mention its .5 or .2 depending on how you do the test. If you increase the amount of water to 20ml instead of 10 does it become .2? (Or .25?)

Is there some particular reason you want to measure that finely? In my opinion it just wastes reagent. (I kind of regret putting it in my instruction sheet, but people seemed to want it.) 0.2ppm in 13,500 gal is maybe 1/2 cup of 6% bleach, it's not worth the trouble to measure that closely; you're micromanaging!
--paulr

 

[Guest]

On the chlorine test, how do you get it more accurate? I see people mention its .5 or .2 depending on how you do the test. If you increase the amount of water to 20ml instead of 10 does it become .2? (Or .25?)

Is there some particular reason you want to measure that finely? In my opinion it just wastes reagent. (I kind of regret putting it in my instruction sheet, but people seemed to want it.) 0.2ppm in 13,500 gal is maybe 1/2 cup of 6% bleach, it's not worth the trouble to measure that closely.
--paulr

I agree with PaulR on her. With commercial setups you might need to monitor .2 ppm CC in public poos and spas because of local health laws but is a whole different ballgame!

 

[Crimson]

I was more just curious rather than actually expecting to do tests to that level of accuracy.