Ashleigh Posted January 10 Report Posted January 10 Total alkalinity is zero, PH is 8.7. There was quite a lot of calcium buildup around the pool as it hadn't been serviced in a while and it's an indoor pool. As advised, I have added 12kg over 3/4 days of alkalinity up which did absolutely nothing to raise the alkalinity of my pool (please note I was told to not run my chlorinator for a few days so not sure if that would affect the uptake or not). My pool person is now saying to ignore the alkalinity reading and try and get the PH down, and as advised I have added 10l of acid to no effect either. Which way do I go now? I've wasted a lot of money so far with absolutely no result Quote
waterbear Posted January 13 Report Posted January 13 How are you testing your water? Most pool testing cannot test a pH as high as 8.7. It is a limitation of the reagent used. What is your chlorine level? Quote
Ashleigh Posted January 13 Author Report Posted January 13 I've been taking it in to the pool shop, and it's also showing high pH on the pool test strips Quote
waterbear Posted January 14 Report Posted January 14 How are the they testing your water? Are they using strips in a reader, a disc that is read in a machine, or some other method. Once again, what is your your sanitizer reading and are you using chlotine or bromine since this is an indoor pool. I have a suspicion that your sanitizer is high (even if it is testing low due to bleachout of the DPD reagents which occurs at high sanitizer levels, which cause false high pH readings because of a chemical interaction between the pH indicator and the high level of sanitizer and can also cause low TA readings because of bleach out of the indicator reagent used for the that test. I need to know what sanitizer you are using and either your total bromine or your free chlorine and combined chlorine readings and need you to do one more thing to eliminate this possibility. Get an inexpensive 2 way (sanitizer/pH) liquid drop based test kit that uses OTO reagent to test chlorine and bromine. They are available at most big box stores like Hone Depot, Walmart, Lowes, Ace Hardware, and many pool stores and online retailers for a few dollars. You will know it is an OTO based kit because the comparator will have yellow color blocks for the chlorine/bromine test and not red color blocks which DPD testing uses. OTO does not bleach out like DPD but only tests total chlorine and not Free chlorine, which is what we want to know which is why DPD is widely used. Test your sanitizer and tell me what color it turns (stays clear, light yellow, deep yellow ,orange, brown). Once we confirm or dispel this possibility we can move on to the next step in getting your pool rebalanced Quote
Ashleigh Posted January 18 Author Report Posted January 18 They have a disc read in a machine and have also cross checked with the pool test strips. We have chlorine. The pool test strips read top to bottom (left is a new strip, right is the used strip to compare) - Total hardness, total chlorine, free chlorine (bromine), total alkalinity, pH Quote
waterbear Posted January 19 Report Posted January 19 The disc is a LaMotte spin disc. It's a decent system as long as the person running the test knows it's limitations. Most do not. It is a DPD test so it is prone to bleachout at high santizer levels and the ALK test has always been prblematic. I used LaMotte water testing when I worked the retail end of the industry so I am very familiar with it and, in fact, went through their training for certification in using it. Their Waterlink computer software is decent but be aware that most pool stores adjust the software to maximize chemical sales since that is how they make money. On 1/18/2025 at 6:29 PM, Ashleigh said: The pool test strips read top to bottom (left is a new strip, right is the used strip to compare) - The pH test gave it away. It's purple, not a shade of red, which means your bromine CORRECTION Chlorine is very high and converting the phenol red indicator to chlorphenol red. Read this: https://www.poolspaforum.com/forum/index.php?/topic/58991-false-high-ph-readings-when-shocking-some-truths/ You will not get an accurate pH or TA reading until the sanitizer comes down. Your pH might actually be very low right now! It seems that your pool store and pool technician are not familiar with this very common interference with ALL pH tests unless an electronic pH meter is used. What form of chlorine are you using? I noticed a salt reading. Do you have a SWCG? If so what brand and what is your CYA level. Even an indoor pool needs some CYA, the reason is technical so I won't go into it here and SWCGs need a much higher level of CYA so the cell does not need to run as mucn. Strips are useless. While they are precise (will give the same results on multiple tests of the same sample), they are not accurate (giving a result that give the correct result for the water parameter being tested). Strips also so not have the resolution needed to properly balance water. For example, TA often has to be adjusted within in a range of 20 or 30 ppm for optimum pH control and the resolution on strips is +/- 40 ppm making them useless for this. The sanitizer test in the K-2006 uses FAS_DPD testing which does NOT bleach out at high sanitizer levels and will directly read FC and CC so no math is needed to determine CC unlike the DPD test that LaMotte, most test strips, and other Taylor test kits other than the k-2006 (chlorine) and K-2106 (bromine). https://www.taylortechnologies.com/en/page/231/k-2006-complete-kit-with-fas-dpd Here are videos on the use of the kit. My suggestion is to get a Taylor K-2006 test kit which uses Quote
Ashleigh Posted January 19 Author Report Posted January 19 It's a Davey salt water chlorinator, installed last year. It's set at 10% currently, I'm not sure what it was set at when it was first installed though (between install and the pool service guy coming out). Is CYA the cyanuric acid? It's saying 5ppm on the test sheet. I'm in Aus so not sure what test kits are available here Quote
waterbear Posted January 19 Report Posted January 19 CYA is cyanuric acid. While it is often said that indoor pools do no need CYA since they are not eposed to sunlight a small omount of CYA (between 20 to 30 ppm) will act as a chlorine buffer and make the chlorine less aggressive and also eliminate the effect of pH on chlorine effectiveness to a great degree. The Davey manual recommends a CYA range of 25 - 50 ppm for an outdoor pool anead says it is not needed for indoor pools but as I said above, there is a benefit to maintaining the CYA at 20 to 30 ppm and maintaining the FC at 3 to 5 ppm instead of no CYA and a FC of 2-4 ppm. IF you cannot get the Taylor K-2006 FAS_DPD kit in Australia or the price is too high (check Amazon and other online retailers) then Clear Choice labs has FAS-DPD kits such as the Total Pool Water Testing Kit, Salt Water and they are based in Queensland. From what I can tell they are using Taylor reagents and repackaging them much like TFTestkits does in the US. Quote
Ashleigh Posted January 19 Author Report Posted January 19 Ok thanks! So how do I reduce the bromine in the pool? Quote
waterbear Posted January 19 Report Posted January 19 I thought you said you were using chlorine and not bromine. The same test is used for both bot if you have a bromine pool the reading would be approx. twice the chlorine reading. You have either one or the other. Which is it? If you have a chlorine pool disregard the bromine reading. If you have a bromine pool and the test does not have a bromine readout or scale then multiply the FC reading by 2.25 to get bromine. I made a typo in my previous response which I have corrected. This is what I get for answering posts at 4 am First we need to determine if you chlorine is really high (and I suspect it is because the strips show a very dark color for sanitizer and the LaMotte DPD test starts bleaching out below 10 ppm and the fact that the TA is low after adding all the baking soda also indicated bleachout -- FWIW alkalinity up is just baking soda (sodium bicarbonate AKA sodium hydrogen carbonate) and is much cheaper at the grocer than the pool store). Checking if the sanitzer is high enough to cause bleachout is best done with an OTO test kit (2 way tester for chlorine/bromine and pH that has yellow blocks on the santizer test comparator). If it is high we can take it from there. These test kits are inexpensive and readily available but of limited use. Determining if high sanitizer is bleaching out a DPD test or testing bromine are their best uses. Since they only test total chlorine they are not that useful for chorine pools other then determining if your chlorine is very high. This is an example of what I am talking about: Quote
Ashleigh Posted January 20 Author Report Posted January 20 So I cannot find an OTO test in Australia, they are all just the dpd tablets. Can I just assume it is high? And what to do next? Quote
waterbear Posted January 20 Report Posted January 20 4 hours ago, Ashleigh said: So I cannot find an OTO test in Australia, they are all just the dpd tablets. A quick Google seach found these: https://mrpoolman.com.au/products/water-technix-5-in-1-test-kit-pool-spa-chlorine-bromine-ph-alkalinity-acid https://www.poolset.com.au/pool-set-5in1-test-kit.html https://www.bestpoolsupplies.com.au/product/737/Pool-Water-Test-Kit-6-in-1 https://www.ebay.com.au/itm/405382704929 https://www.ebay.com.au/itm/166946602847?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D279336%26meid%3D5ffa198a171e49caa9a907d0a3c14e69%26pid%3D101875%26rk%3D4%26rkt%3D4%26sd%3D405382704929%26itm%3D166946602847%26pmt%3D1%26noa%3D0%26pg%3D2332490%26algv%3DSimVIDwebV3WithCPCExpansionEmbeddingSearchQuerySemanticBroadMatchSingularityRecall%26brand%3DUnbranded&_trksid=p2332490.c101875.m1851&itmprp=cksum%3A1669466028475ffa198a171e49caa9a907d0a3c14e69|enc%3AAQAJAAABQNthdh9o32sOfKme0krmx3yc5y0DRWWwwpiraCEsA5rOcanQjqu91drTeDElZLF31uaWQXaQ2pNTl5IMyA1OfooQwqEcJUvtG9LvKPKHgcRzphx12iPvBSva61o%2BMhuWL%2F159NOALpZmmVOgiYanH32fPmC7YiVdgsCP07bsQSJyiPtc9eCLBuuuxUJog3mK9sbxHLPaKnctlrdOenYog524XAWayHbuM3kvSBWavUsmGTezfmrveGABYxRAXBPLifi00Z9IO7tsocoBrnFqFuK5vUdwdox%2FSErstVN4wNfxIY7HHEK8IMc6L6pJ9XMvDuj5G%2FsbYmTxFfvHpgNzoSU%2B%2F7w1DeNhosUXN48hONI8b641tNgffdx92ypDRz9PZixckG3zE5gdvEbrZHoLyw2VzTlr6hegOL8%2B2ciJ1thI|ampid%3APL_CLK|clp%3A2332490&itmmeta=01JJ11QZ6SERJMKKVB57Z6ADAH The first three are based on the Taylor 1000 serires kits (They look like rebranded Taylor kits) but even the cheapest one from eBay will do the job. You just want the OTO reagent and comparator and we will not be using the color blocks. If the color is yellow your chlorine is not high, if deep yellow it is high and can possibly cause partial bleachout and inaccurate pH readings. If the color is orange to brown your chlorine is way too high and bleaching out your DPD and TA and causing totally incorrect false high pH readings. As an alternative to the OTO test you can test with DPD but dilute your sample with distilled water. Start with a 50/50 mix of pool water and distilled water and test chlorine and multiply the results by 2. If it still is testing low then dilute 1 part pool water with 4 parts distilled water and multiply your results by 5. These procedures are a pain but can tell you if your DPD test is bleaching out if you don't have an OTO test. If you just want to assume that your chlorine is high or if either OTO or diluting DPD shows it's high then turn of the SWCG. If the pool is covered uncover it, circulate continuously and you can either add a chlorine reducer (sodium thiosulfate) or hydrogen peroxide (used an oxidizer in biguinide sanitizer systems but I don't know if they are used in Australia. In the USA they are under such brands as Soft Swim, Revacil, and Baquacil.) Monitor pH as you use the chlorine remover and if my suspicion is correct you will see it drop on it's own. It's not really dropping, you are getting accurate pH readings without the chemical interference from the high sanitizer, You should also see the TA increase because the indicator is not bleaching out. . Quote
Ashleigh Posted February 3 Author Report Posted February 3 So update 😅😅 It took 7.9kg of sodium thiosulfate to get the chlorine back to normal, which put my chlorine level at over 130ppm. After that, the alkalinity and PH only needed minor adjustments. Quote
waterbear Posted February 3 Report Posted February 3 Also be sure to set the SWCG lower so this does not happen again and fire your pool person. They should have caught this! Quote
Ashleigh Posted February 3 Author Report Posted February 3 It hadn't been serviced in a while so unfortunately just a series of unfortunate events and neglect, plus a lack of knowledge about the limitations of the testing equipment. Yes the chlorinator will be started at 10% and adjusted higher from there if need be 1 Quote
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