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Hi, I've been using borax as my sole means of raising TA with the understanding that it also serves as a natural algaecide.
Would it be accurate to say that, if I keep TA in the 60-90 range, I am also keeping sodium tetraborate within appropriate bounds? I haven't found any way to measure sodium tetraborate, so I don't want to raise sodium tetraborate levels too high.
Thanks so much,
R. B.
We typically suggest using baking soda and not Borax to raise alk.
[URL="http://www.amazon.com/exec/obidos/ASIN/B004KZNPL2/poolbooks"]LaMotte borate test strips [/URL]are the easiest way to measure borate level. They are much easier to read than the AquaChek borate strips. If you are testing with a Taylor K-2005 or K-2006 there is also an add on drop based borate test kit available from Piscines Apollo in Canada that is excellent and more precise than the strips (even though the strips have enough precision for our purpose). This test uses two of the reagents and the comparator in the Taylor kit so it is not a stand alone borate test. You must have one of the two Taylor kits to use it (and should have a K-2006 anyway!) IF you have a TF-100 test kit from TF test kits this add on will not work since you do not have a 2000 series comparator.
Borax raises pH but has very little impact on TA compared to sodium carbonate, the usual pH increaser in pools, and no impact on adjusted TA (since it does not add any carbonate alkalinity at all) so if you are using it to raise TA you probably are adding WAY too much to your pool (once again , since it does not affect carbonate alkalinity it does not dissipate into the atmosphere by out gassing of CO2! ) The effective borate range for its benefits as an algaestat and pH buffer is 30 to 50 ppm and when added n this quantity the pH rise will need to be countered with the addition of muriatic acid at the same time.
HOWEVER, as Watermom said, the PROPER chemical to raise TA is baking soda (AKA sodium bicarbonate or sodium hydrogen carbonate).
Borax is used two ways:
1. to raise pH with less impact on TA than sodium carbonate (pH increase)
OR
2. when added in a 30 to 50 ppm concentration with muriatic acid to counter the pH rise it is an algaestat and SECONDARY pH buffer that works together with the bicarbonate pH buffer that we call TA
Just one further note: unless you have a concrete pool, the ONLY reason TA matters is if (a) it's TOO high, or (b) if your pH is bouncing around or changes too rapidly to keep it under control.
If you have a vinyl or fiberglass pool, and are NOT having problems controlling your pH -- it's normal to have to add something up to 1 - 2x per week to keep the pH in range -- then do NOT worry about your TA!
Hi,
I sent a response yesterday but it's not showing up on the thread. Let me try again.
First, thank you so much for the information and advice.
I have a plaster pool that always trended toward alkaline and is doing that more so since replastering last fall.
That replastering was the impetus to research the BBB method. I came away from my research with the notion that using Borax was better than baking soda because it had the benefits of raising TA, buffering/stabilizing PH, and acting as an algaecide. (It has certainly raised my TA readings.) The caveats were that it takes a lot more borax and it had to be mediated with muriatic acid. Perhaps, this use of borax was a minority opinion and I got the wrong impression but my pool performance has been stellar.
In any event, I am concerned now that I may have too much borax in the pool. Can do this cause damage? If so, what can I do? (For sure, I'll order some strips.) Thanks again, Rebecca
I don't think you're going to have to worry about damage because your Borates are too high--it takes LOTS of Borax to get to that point anyway! As long as your pH is okay, your TA is ok, then just order some Borate test strips to find out what your borate level is. If it needs to come down, it will do so as a result of water loss--splashout, filter cleanings, etc. If it needs to come up, then you already know how--you are shooting for 30-50 ppm.
I think we were all just a bit confused by your original post, because Borax is generally used to raise the pH, NOT the TA. Sometimes new posters confuse the two, and we were trying to make sure you hadn't. The use of borates through Borax addition has been shown to stabilize pH and act as a secondary barrier to algae, so as long as you understand why you're using it, which you obviously do, then it's all good! :)
Janet
HOw are you testing your water otherwise? If you are using strips I would strongly recommend getting a Taylor K-2006 test kit. Also, post a full set of test results. so we can see what is going on in your pool.
New plaster will cause pH rise because the curing process (which can take a year to complete) produced alkaline material in the water. Once the plaster fully cures the pH becomes more stable. If you needed to replaster the pool because of water balance issues then we really should see your current numbers, IF your pH was normally rising before the replaster then your TA was too high. Period. However, with new plaster this is not necessarily the case. Your test resutls (not done with strips please!) will tell us more.
I had to replaster because it had been about 20 years! I'm using a HTH 6-way test kit which is basically the Taylor 2006 packaged under the Wal-mart brand name for about half the price.
Speaking of testing, I've been looking all over this morning for those LaMotte borate test strips and can't find them anywhere except in bulk through LaMotte. Where are ya'll getting them?
If I can find them, then I can answer my own question: If you use borax to put TA within the desired range, are you also automatically putting sodium tetraborate within desired ranges?
In the meantime, I'll breathe a little easier in the hope that I probably didn't get sodium tetraborate too high and even if I did, it might not matter.
Thanks,
Rebecca
Click on the testkit link in Ben's post above. You can get the test strips there.
I can't agree with you here. The most significant difference is the K-2006 provides FAS-DPD testing for Free Chlorine and Combined Chlorine, the HTH 6-way from wall mart provides OTO testing for Total chlorine. Both tests have a place, but, when shocking a pool or running CYA levels over 50 you need FAS-DPD.Quote:
Originally Posted by Rebecca
HTH 6-way has OTO testing, which is desirable for daily testing, but (as Dave notes) doesn't replace the FAS-DPD test. Also, the 6-way tests TOTAL hardness, not CALCIUM hardness. (K2006 tests calcium). And the 6-way only has enough reagent for 3 CYA tests, instead of 9 (I think) in the K2006.
I'm learning a lot... Thanks for helping me finesse.
1. Okay, I see. Here's the actual product link:
http://www.loveyourhottub.com/lamott...a-test-borate/
2. You can buy a Taylor refill for the cyanuric acid (very cheaply) and use with the HTH kit.
3. I haven't shocked the pool since going to the BBB approach. I try to run CYA at 30-40.
4. Frankly, I assumed that calcium hardness and total hardness were either the same or equivalents, since the HTH kit says the remedy for low hardness is adding calcium. Please continue my education.
Rebecca
Total hardness is calcium and magnesium hardness. With plaster pools we are only interested in calcium hardness since if the calcium is too low the water can be aggresive to the plaster finish. Totql hardness is really a useless test for pools (strips only measure total hardness also.)
Also, OTO only tests total chlorine. FAS-DPD tests free and combinced chlorine, is not a color matching test but rather a drop counting test similar to the TA and Hardness tests and can directly measure chlorine levels as high as about 50 ppm with a precision of either .5 or .2 ppm.
Calcium hardness/Total hardness.
Has anyone actually experienced a situation where they had high hardness but low calcium hardness? I know its theoretically possible but I suspect it's rare. I think the principal contributor to magnesium hardness in water is dolomite. As I understand it, very large concentrations are rare on Planet Earth. In my area, dolomite is associated--in a limited distribution--with lead and zinc mining.
When I filled my pool after resurfacing, total hardness was low. I can't remember the exact number but it was less than 100. It was probably 70 because that's what our lake water tests at. I suspect that hardness is largely calcium based because of limestone formations under the lake and in watersheds. I added calcium carbonate. The water hardness increased to about 220 and has since risen to 300 without any additional calcium carbonate.
Where did the additional hardness come from? As it happens, I harvest rainwater from a roof into the pool. Apparently, ground or pulverized limestone (calcium carbonate or GCC) or dolomite (calcium magnesium carbonate) are used extensively in asphalt shingles. So it looks like I have a situation that may call for calcium hardness testing. Thanks for alerting me to this. Rebecca
Unfortunately, Chemtura (BioGuard, AquaChem, many other brands) and especially Arch (HTH, other brands) have begun using magnesium sulfate to 'dilute' their calcium hypochlorite products. I think they may be using it elsewhere, too.
Regarding rain water -- I don't know if distilled water (rain water) could dissolve significant amounts of calcium and magnesium in the manner you imply. I'm guessing not, since roofing doesn't fail by losing all its grit. But you could check by testing the water you collect.
Good thoughts on the improbability of dissolving magnesium.
I have been completely flummoxed about actual calcium hardness in my pool. The old total hardness kit used to give me a reading of 200-250. Per your advice, I switched to the Taylor 3 bottle approach, measuring only calcium hardness. It definitely turns red after adding 20 drops of #10 and 5 drops of #llL. So there is some calcium hardness present but I am not able to discern any change in color after adding #12. At first, I thought maybe there was a very very subtle shift in color to lavender but now I've done this test a lot of times and feel very uncertain....
To make this more complicated, the old total hardness test is not showing any hardness so I assume the chemicals have gone kaput.
Thank you, Rebecca
If yo had no calcium hardness present the color would not turn red when adding the indicator. It would stay blue. It just means you have not added enough titrant to reach endpoint.
My suggestion is use a 10 ml water sample, add 10 drps of calcium buffer R-0010, 3 drops of calcon indicator R-0011 and then every drop of EDTA titrant R-1012 would equal 25 ppm calcium hardness instead of 10 ppm. Therefore every 4 drops is 100 ppm so the test will go much faster, particularly when calcium levels are very high.