Measuring borate levels - Lamotte strips REALLY hard to accurately read.

[lalittle]

I'm trying to use the Lamotte test strips to test for borates, but I'm finding it to be effectively impossible to get accurate results. I just can't tell with any sense of accuracy what color actually matches the strip. It's one of three colors, which doesn't tell me much. I've read about drop tests for borates, but they are either discontinued or somewhat prohibitively priced. Other than really obvious things like using good light, are there any "tricks" to getting more accurate results from the Lamotte strips, which I keep reading are the best of the strip tests for borates? Does anyone have any better luck with any other borate tests, strips or otherwise?

On that note, does the Lamotte test get easier to read as the level of borates rises? At the moment, I'm honestly not sure what the borate level in my pool is because I don't know what the previous owners did. If I had to guess I would say it's probably zero, but using the test strips it looks like it could be anywhere between 0 and 30. Is it more difficult to read a "0" level of borates than it is to read a "30" or "50"? In other words, would be easier to tell if it was "30" if the level was actually 30?

I'd like to add borates to help control pH rise in my pool, but I don't want to do this unless I can confidently measure the level.

Thanks,

Larry

 

[chem geek]

The previous owners probably didn't use borates and if your reading looks like it might be 0 then it probably is.

You can post a photo of the strip next to the bottle if you want us to give you our best guess. If you want to use a drop-based test, it isn't available in the U.S. except for an expensive Taylor K-1541 that is more sensitive than you want. This post describes how you can use your existing Taylor kit with the addition of Mannitol powder and Bromothymol Blue.

 

[lalittle]

I'm a little confused about how other people do this. Do people just do the best they can with the strips and not worry about being 30 or so ppm off in their measurements? At this point I just can't see how anybody could read the strips and not potentially be this far off.

 

[chiefwej]

The target for borates is around 50 ppm. I just used the Pool Math calculator to determine how much to add. It's not very critical. If you have 40 ppm or 60 it really wouldn't be much different. Just assume you have no borates and add what ever it would take to reach the desired level.

 

[lalittle]

The target for borates is around 50 ppm. I just used the Pool Math calculator to determine how much to add. It's not very critical. If you have 40 ppm or 60 it really wouldn't be much different. Just assume you have no borates and add what ever it would take to reach the desired level.

I'm not worried about the first dose given that I think it's safe to assume a current level of zero. What I'm worried about is keeping it at a consistent level after draining and refilling for various reasons. I get enough rain to force me to have to drain once in a while, and I'll have some repairs later in the year that will require some draining as well. Add to this the loss from cleaning/backwashing the filter, and it won't take long to lose track of the borate levels in the pool, at which point I'll need a reliable way of testing. At the moment, I don't feel like I have any means of accurately doing this.

 

[JasonLion]

The borate level is not all that critical, anywhere around 30 to 50 is fine. Thus the lack of precision in the test is not usually an issue.

If you really can't make any sense of the borate test result, and don't normally use any chemicals that contain CYA, you can use the CYA level as a proxy for the borate level during the season. All the normal things that causes CYA to go down will also cause borates to go down by the same percentage. That isn't perfect, because CYA does break down very slowly, but it is good enough during the season. Over the winter CYA can vanish, so I wouldn't count on that relationship across seasons.

 

[RobVos]

I also am having a difficult time determining the borate level. I want at least 50, but not sure what I have.

Dropbox - 2015-06-03 18.12.25.jpg

Not sure if this link will work - I am on an original iPad and I can't seem to upload the file directly.

 

[lalittle]

Yeah -- that picture is a pretty good example of how difficult it is to tell with any semblance of accuracy what your borate levels are. If I had to guess, I'd say you were looking at around 50-ish, but it's just really hard to tell. I can honestly say that if you told me that the "actual" level was 80, I wouldn't be at all shocked. I know that the level isn't critical, but with this test, you can be off by fully double the amount or even more.

L

 

[chem geek]

I'd call it 50, but it's hard to tell.

 

[lalittle]

It's definitely somewhere between 1 and 100,000. I'd stake my reputation -- and chem geek's as well -- on that.

L

 

[bdavis466]

I followed Chem Geek's instructions with the mannitol and Indicator dye and it is definitely more precise (if I did it right).

What worked for me:

25 ml sample
5 Drops of R0009
10 Drops Bromothylmol Blue (water turned very faint yellow)
2 Drops R0010 (water turned light blue color)
1/4 Tablespoon of the Mannitol power (water turned very very faint yellow)
Count drops of R0010 (water turned very very light blue)

I counted 10. 10x4.5=45. I added the boric acid per Pool Math to a level of 50 about 2-1/2 months ago, so the result seems like it would be correct.

This test is probably +or- 5-10. Even if it is 10, 10 is far better than +or- 30 (or even more) that the strips provide. I had a hard enough time telling the difference between 30,50, and 80 with the strips.

I have turned into a CSI maniac and wasn't satisfied with "close enough" with the strips since everything taught here is aimed at being precise. Borates can definitely effect the CSI so I'd rather know a little more closely what is actually in the pool.