Borate Test

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This is more specifically for Matt, aka Joyfullnoise, but anyone who is doing the test already works as well :) I also hope others trying it the first time may get some help with the same questions if they hit it.

I'll copy the instructions at the bottom or on a reply, but first the questions.

Here's me chemistry right at the time of the test, incase some of it could have effected my result:

FC - 6
PH - 7.1
TA - 40
CH - 80
CYA - 60

I've been waiting for the things I needed to test borates before touching PH or TA, but I need to get those fixed.

Anyway, I found the cleaned up instructions from Matt to be excellent!!! Big thanks to him, as well as all those in the old thread who took part in figuring it out. WAY over my head trying to read everything in the old one, lol.

On step 6 when I added the mannitol it BARELY turned yellow, or at least nowhere near to the yellow obtained in step 4. Is that ok, or should I use more powder next time?

On step 7 I hit a shade of blue just a TAD darker than the blue in step 5. Two drops at 7.9 is 15.8 if the above didn't skew it much. When I initially added last season I used the calculator and "should" have been around 50-55. However, with our 65 inches of rain a year on top of backwash and splashout the current level seems reasonable. On the test strips where I have all I can do to tell the difference between 0 and 80 I had guessed it to be around 25 so in the same ballpark.

Other than looking over my shoulder as I do it, does the above look correct? Specifically, step 6

Thanks again!!!

- - - Updated - - -

Test Procedure
1.) Collect a 25ml sample of pool water
2.) Add 2 drops of R-0007 to neutralize the chlorine
3.) Add 5 drops of R-0009 to lower pH and neutralize carbonate alkalinity
4.) Add 6 drops of BTB until the water turns yellow. You can use more than 6 drops if the color is too faint. The drop count here will not affect the results of the test.
5.) Add 2 drops of R-0010 until the water just turns pale blue. This is the hard part - try hard to remember the shade of blue here.
6.) Add 1 level spoonful (1/8 teaspoon) of Mannitol. If the water has boron/borates, then the sample will turn yellow again.
7.) Add R-0010 drops until the water turns into a similar shade of blue from Step 5. Record how many rops of R-0010 are used in this step.
8.) Calculate ppm boron/borates by multiplying the number of drops of R-0010 used only in step 7 by 7.9 for total ppm

Alternative Test Method Volumes
1.) Collect either 25ml or 50ml
8.) Calculate ppm boron/borates by using these formulas
For 25ml sample, each drop of R-0010 used only in step 7 equals 7.9ppm
For 50ml sample, you'll need 3 drops of R-0007 in Step 2, 7 drops of R-0009 in Step 3, 2 level spoonfuls of mannitol (1/4 tsp total) in Step 6 and each drop of R-0010 used only in step 7 equals 4.0ppm

Notes:

*Dechlorinating the sample is important. The bromothymol blue (BTB) dye is sensitive to chlorine and will be bleached by it. 2 to 3 drops of R-0007 is usually more than enough for FC in normal ranges.

*If your pool water has very high levels of TA (>100 ppm), I would suggest experimenting with the the number of drops in Step 3. It is important to get the sample down below the transition point for the BTB indicator and a high TA water sample will make it necessary to use more drops of R-0009.

*The amount of bromotymol blue (BTB) used in Step 4 should be adjusted to give you the best color shade you can see. 6 drops of BTB is just a starting point, use more if needed.

*The R-0010 reagent (sodium hydroxide) has a very STRONG effect on raising the pH. So it should not take much to go from pale yellow to blue in Step 5. You don't want to overshoot this and add lots of R-0010 in this step. It would be easier if the R-0010 were less concentrated but we're stuck with what we have available.

*You can add extra mannitol powder as well. The point is to have excess mannitol powder in solution so that all of the boron reacts with it. Using too little will give you a false-low result.

*Yes, you have to try to remember the shades of blue unfortunately. This isn't a true "end point" titration but rather a color matching titration so there is a bit of subjectivity to it. I would suggest doing the test several times until you feel you are comfortable with it. So stock up on your R-0009 and R-0010 if you only have small quantities.
 
I haven't calculated your CSI but, given where your numbers are, your water is pretty darn towards plaster (yes, I know you have a vinyl pool). Do you intentionally keep your water that low in CH?

I'd recommend you get your water chemistry up to TFP levels BEFORE you add anymore borates.

What are you planning to add, borax or boric acid?

As for the faint yellow color, that is just a consequence of the low concentration of borates. The intensity of the yellow is related to the concentration of the borate anion. When the borate anion combines with the diols in the mannitol molecule, it creates an acidic reaction that causes the BTB indicator to turn yellow. So, if you had zero borates in your water, adding mannitol would not make the solution turn yellow.

As for getting the shade of blue right, that is the hard part. It's made harder by the fact that the R-0010 is fairly strong and raises the pH a lot with each drop added so it's very easy to overshoot the blue color you want.
 
BTW, life is busy here with our new baby so PM me next time if you want me to respond to a specific post. I'm mostly on Tapatalk and I can easily miss a post that is intended for me.
 
Borax. I have plenty on hand :) I have pretty much anything I need, other than bleach my wife keeps stealing for the wash :(

Won't borax increase my PH and at least slightly raise TA? That's why I was waiting to see what it was first anyway and thinking I'd add what borax I could without PH getting to high first, then us borax and MA together for whatever borax need remained, then bring TA up.

You're the expert though, I should have posted and asked before waiting for the new stuff to even test the borates since it apparently dropped so far :)

With a vinyl pool I hardly ever test CH. It was 180 when I bought the house last Spring and was 160 at the end of July. I tested it late Feb and was down to 80, 80 again today, and I tested a second time today and got 80. Not that they ever get it right, but my one and ONLY pool store water test was late Feb as well and they came up with 80 as well. I did read here that foaming could become an issue so was thinking it may not hurt to bring it up to 100.

Otherwise, I'm more confused. I though plaster pools needed a high CH, but not an extreme, so why would mine be towards plaster with it so low? As for the levels, my fill water is TA 50 and CH 60, but with so much rain here I don't even use it much and mother nature gives me zero, lol.
 
No worries. I see what you're up to now. Using borax in your pool is the right approach since your pH and TA are low. Borax doesn't add that much to TA so keep an eye on your TA as you do your borax/MA additions.

As for my comments regarding CH, I was just thinking that if I took your water and put it in my plaster pool, the CSI would be so negative that it would dissolve my plaster. In your vinyl pool, it's perfectly fine. I do think that a CH of 80 is borderline low for your pool just from a foaming perspective so it's up to you if you want add CH or not. I wouldn't let it get below 50ppm but that just my personal opinion.
 
Ok, thanks again!!! I'll add the tiny bit of borax needed to get PH to around 7.5 tonight. I MAY need more MA than I have so I'll re-test everything tomorrow so I can run out to get more MA I'll likely need and take care of adding the rest of the borax and the MA Saturday morning, other than shooting a little low and make a small adjustment in a week or so. I'll take my time over the weekend while making additions and keep an eye on TA and PH both, but save any final TA adjustment until the end unless it's WAY out of whack. I know LAST Summer, with TA at 60 which fell to 50 by end of Summer the PH stayed at 7.5 like it was anchored, but we aren't using it yet so there's no splashing and no grandson begging for the "sprinkler thingy" so PH should come up from that as well.
 
Well, apparently I didn't have as much on hand as I thought :( I knew my wife was snagging my emergency bleach stock without replacing them. Is supposed to be 4 gallons at all times and replace whatever goes to the laundry and keep it fresh with the rotation.

LOL, now that borax is on premises she's using some of that in the laundry now too!!! I added enough I should be up to around 35ppm now though based on pool math. I'll test again tomorrow and she's bringing home six boxes this evening after work so I should be good to finish it up :)

New heat pump has been running a little and water up to 81 and pool in use already, woo hoo!
 

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Thanks again to Joyfulnoise, along with Chem Geek and the others who all worked on figuring out how to do this test. I'm all done now and it was much more comfortable than squinting at a test strip and guessing :)

I used the larger volume test and it looks like I'm at 52 for borates now. PH at 7.6 and TA at 60, back to where I was all last Summer once settled and never seems to drift much at that point.

Only thing left is to double check all tests tomorrow in case some things haven't fully dissolved and any minor corrections :) Pool now up to 83 as well and all ready for my daughter and Grandson to arrive for their vacation on Tuesday!
 
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