Total Alkalinity confusion and well chemistry in general

ajup2it

Well-known member
Sep 3, 2019
73
Indiana
I'm in the process of SLAM and I just got the test kit. I'm trying to understand what I'm doing as I'm new to having a pool and I'm not a chemist or mathematician. So I think I did the FC, CC and TC correctly. My CYA is a bit low perhaps, but I felt I did this one correctly too. Its the alkalinity that has me stymied because it never did turn red. It went from green to yellow. I used the speed stir and kept adding the drops as instructed on the kit and this website. I couldn't get it to go red - ever. I did read that for high FC it could just stay yellow but if that's the case, I'm still unsure (50 drops or 72 drops??) which yellow was the right one? I'm lost and could use a bit of help and patience.

My attempt at testing (feeble though it may be):
FC 76 drops *.05 = 3.8 (so on pool math, would this be 38?)
CC 3 more drops to go clear again * .05 = .15 (or do I add the three drops to the 76 = 79 then multiply by .05??)
TC = 3.95??
CYA 45
TA 50-76 drops at yellow *10 = 150-176??

I'm so lost. Thanks in advance for any help.
 

thetekgeek

Bronze Supporter
Jun 8, 2018
171
Nebraska
Are you sure you used the correct reagents? 10 drops of R-0010 (swirl), 3 drops of R-0011L (swirl), then R-0009 one drop at a time until it turns bright pink or "red".

I have never had it even turn remotely yellow, so I am leaning towards an incorrect use of a reagent.

76 DROPS on the FC test would be 38 PPM. That is pretty high, even for a SLAM. Make sure you are following the FC/CYA chart. Your SLAM level should be 20 ppm FC. Don't worry about TC. But, to answer your question about TC, you would add 1.5 to 38 for a TC of 39.5. CC is 1.5. The multiplier you should be using is 0.5 not 0.05.
 
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ajup2it

Well-known member
Sep 3, 2019
73
Indiana
I swear I used the right reagents, based on the instructions given to me by TFTestkits. See screenshot. It says two drops of R-0007, then 5 of R-0008. Then 1 drop at a time of R-0009. The bottles are also labeled Alkalinity Test as well. Did they send me the wrong stuff? Even the video says the same numbers I used:
I'll try it again.

Thank you for clearing up FC for me. I misread that and was quite confused.
 

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thetekgeek

Bronze Supporter
Jun 8, 2018
171
Nebraska
Sorry on the amounts. I was going from memory and mixed up the number of drops. Here are the instructions for the TA test from the TFtest kits website.

Total Alkalinity test – TA has a buffering affect on pH, preventing it from moving suddenly. Good TA readings will be around 70-90 for salt pools and 100-120 for normal pools
1. Rinse and fill the clear plastic cylinder to the 25ml mark
2. Add two drops of R-0007 and mix. Then, add 5 drops of R-0008 and mix again. Solution will turn green.
3. Add R-0009 one drop at a time, swirling between each drop. Wipe the tip of the bottle after every drop with a damp cloth. Continue ‘til color changes to red. Multiply the number of drops you added times 10. (11 drops = T/A 110) Record it. TA can vary widely. but a range of 70-120 normally works well.


NOTE: In the presence of high chlorine, initial color may be blue and shift to yellow. Test is still valid.

I had never noticed the NOTE on the instruction card, but it appears that the color change to yellow is still a valid test.
 

ajup2it

Well-known member
Sep 3, 2019
73
Indiana
No worries. UGH with the yellow though, its so pale and hard to tell when it changes. I'm going to have to run it a third time and see when it switches in a different light I guess.

Have you (or anyone else) used the pH tester? If so, how in the world do you calibrate this thing? Guess I should have taken Chem 101 in college. -:eek:- Trying to understand this stuff is a challenge. o_O
 

thetekgeek

Bronze Supporter
Jun 8, 2018
171
Nebraska
I wish I could help you on the PH tester. I do not have one. One warning about PH testing, high FC (above 10) makes the drop test read incorrectly and I don't know if that is true for the handheld tester.

Another thought I have on TA, if you let your FC drift down to the actual SLAM level for your CYA of 50 (20 FC) or even down to normal level (6-8) you could redo the TA test and see if you get a different result. Your FC should drift down in a day or 2 in the sun (faster if you have algae). While you are in SLAM mode, most tests are not needed other than FC and CC. However, you should test and lower your PH to 7.2 before you begin to SLAM. While in SLAM, do your best to not add more chlorine than is needed to reach SLAM level, doing so risks bleaching your liner and is wasting chlorine since much of it will be consumed by the sun.
 
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duraleigh

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Disregard the pH test.....your FC is sky high and skewing the test.
YOur TA test is valid. You are looking for a complete color change, regardless of what it changes to. You have high FC in the pool that is causing that.
Why is your FC so high?
 
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ajup2it

Well-known member
Sep 3, 2019
73
Indiana
@thetekgeek Ah, good to know because it "appears" that my pH is at 7.5, which is where I would have expected it to be. I made sure my pH and TA were dead on the recommended numbers before beginning the SLAM (as much as I was able to given the pool companies test at the time - however, I did try out three different places and the one I used seemed the closest to accurate...for whatever that's worth).

Well its wicked hot today and sunny so here's to hoping for the FC to slide down a bit. I see no algae, have brushed and cleaned behind the pool light. Fingers crossed that I'm headed in the right direction.

@duraleigh - Thank you! My TA is sitting at 160, which is a bit high clearly. FC is high as well likely due to adding too much chlorine in an attempt to kill off the mustard algae once and for all prior to my getting the test kit. Should I add fresh water to the pool to help bring the FC down or let the sun work its magic?
 

thetekgeek

Bronze Supporter
Jun 8, 2018
171
Nebraska
@ajup2it don’t kick yourself for not knowing all this already. There’s a learning curve and we’ve all been right where you are. The good news is you’ve found the best place for learning and you’ve already got a solid test kit. You’ll be a pool pro in no time!
 
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ajup2it

Well-known member
Sep 3, 2019
73
Indiana
Well, I can only hope. Do I leave my water "rest" for now and let the FC come down naturally or help it by adding tap water? Thoughts?
 

beautifulpool

Well-known member
Jun 2, 2019
115
North TX
I'm in the process of SLAM and I just got the test kit. I'm trying to understand what I'm doing as I'm new to having a pool and I'm not a chemist or mathematician. So I think I did the FC, CC and TC correctly. My CYA is a bit low perhaps, but I felt I did this one correctly too. Its the alkalinity that has me stymied because it never did turn red. It went from green to yellow. I used the speed stir and kept adding the drops as instructed on the kit and this website. I couldn't get it to go red - ever. I did read that for high FC it could just stay yellow but if that's the case, I'm still unsure (50 drops or 72 drops??) which yellow was the right one? I'm lost and could use a bit of help and patience.

My attempt at testing (feeble though it may be):
FC 76 drops *.05 = 3.8 (so on pool math, would this be 38?)
CC 3 more drops to go clear again * .05 = .15 (or do I add the three drops to the 76 = 79 then multiply by .05??)
TC = 3.95??
CYA 45
TA 50-76 drops at yellow *10 = 150-176??

I'm so lost. Thanks in advance for any help.
As you stated being in the SLAM process, Could your FC test results be reflecting a false low?? When excess residual chlorine is over 10ppm, & because ☝Of the ✌Dyes in Taylor’s TA color indicator is organic, beware of the possibility of color indicator bleaching out....
You could color change As Blue to yellow vs Green to red.
Also, oddly in some dpd chlorine tests when testing for chlorine in high chlorine ppm samples, indicators can bleach giving false Low chlorine ppm-or even 0.