I just tested again...I get 90. We had it tested at two different stores today and they both said it was 30-50 and the strips come out low. I know neither of these are as accurate as the melanine test, but I can't understand how it got so high. On Friday, I had 0 CYA (well <30 I guess to be totally correct). We NEVER have used trichlor or any other stablizer in our pool. I took the advise to add some to protect the chlorine level. Following the label and the Pool Calculator (which said to add 2.5 lbs per 10,000 gal to achieve 30 ppm), I added 7.5 lbs which is short of the 8.75 pounds that was called for because I wanted to be careful not to overshoot. Now my home reading is around 90 ppm. I don't understand. Is there anything that would interfere with the CYA test?
Newbie - Green water
- Thread starter crawlejg
- Start date
crawlejg said:
I focused in on these points of your first post....
What kind of shock did you use? Granular or powder? There are granular forms of shock that contain CYA.
The initial tests for CYA - the ones that showed zero, were these strip readings or was it a Taylor test that used reagents?
I've read through the thread and there are parts missing or left out. I hate to say it but you need to focus and answer FPM's questions as she asks them. One in particular that I didn't see the answer to was how did you get from a CYA of 100 to less than 30? I'm sorry if I missed where you answered that. We really do want to help but that requires that you tell us what we ask so we can proceed through this in a logical manner.
I may have been unclear before. I haven't gone from 100 ppm CYA to less than 30. The 0 (or less than 30 ppm was measured Friday - with a Taylor kit and the 100 ppm was measured after adding the CYA). For the past two days, I measure approx. 90-100 whenever I test the CYA at home using my Taylor kit. Three different pool stores and the strips I have at home all put me in th 30-50 ppm range. But, I now understand these values to be unreliable in comparison to my Taylor kit test. You have pinpointed my CYA problem.Bama Rambler said:
I had not considered that the "shock" that I used might contain CYA. As it turns out, I had grabbed some 'pace clear shock' at Costco. It contains Sodium Dichloro-s-Triazinetrione Hydrate. Ugh! I didn't know that was CYA. I have used a total of 24 pounds of the stuff. According to the Pool Calculator, that would increase my FC by 45 (which was initially at 0). I think dichlor adds 9 ppm CYA for every 10 ppm FC rise. If that is the case, then my CYA would have increased to 41 ppm. I added 7.5 lbs of CYA (not knowing at the time that my shock had CYA in it). This would have increased CYA by roughly 25 ppm. So, in theory, I should have 41+25 = 67 ppm. Certainly closer to what I have been reading. Just out of curiosity, with the pool now turquoise, but cloudy (presumably from dead algae), would that affect the test since the water is cloudy to begin with? It could account for the 20 ppm I am reading different from what the math says it should be. As for the overnight FC test, I cannot find FAS-DPD reagent in town and had to order it from TFtestkits. It should be here in a couple days, so for now, I have to rely on my strips keeping it above 10 ppm. On that note, I have not had to add shock for 3 days now and it is still >=10 ppm FC. Looks like I have no choice but to drain 1/3 - 1/2 of my water. That cheap shock at Costco is going to cost me a fortune in the end. Lesson learned. 
Well, at least we solved that mystery 
to see if the cloudy water is affecting the results of the CYA test, you can pour straight pool water into the view tube. If the water is cloudy and somewhat obstructs the dot, then you can assume that yes- some of the level is the pool water itself (however, I don't think that's what you'll find - I think you'll find the water is pretty clear.)
Your CYA could have been between 10-20- since the tube starts at 20, it could be that it just wasn't high enough to register on the test but some was present. That is most likely the culprit.
Well, hopefully by the time you complete the partial drain/refill your testing reagent will arrive
to see if the cloudy water is affecting the results of the CYA test, you can pour straight pool water into the view tube. If the water is cloudy and somewhat obstructs the dot, then you can assume that yes- some of the level is the pool water itself (however, I don't think that's what you'll find - I think you'll find the water is pretty clear.)Your CYA could have been between 10-20- since the tube starts at 20, it could be that it just wasn't high enough to register on the test but some was present. That is most likely the culprit.
Well, hopefully by the time you complete the partial drain/refill your testing reagent will arrive
Is refilling 10,000 gal or so out a well advisable? If not, any idea how much it costs to have water trucked in? Should it be pre-chlorinated from a pool water place, or should I try to find someone that can fill up a tanker from a fire hydrant? Thanks again.
I have no idea about the costs of having it trucked in; I imagine that varies from region to region. I am not familiar with the well capabilites - hopefully someone with more experience in that area can advise...
Sneaky, isn't it? I've been trying to get the manufacturers to explicitly add the effective CYA content for stabilized chlorine and the CH content for Cal-Hypo and they could even add the net resulting salt content as well (along with the chlorinating liquid and bleach manufacturers), but they just say that they are limited by the EPA that regulates labeling via FIFRA rules. However, such rules do not require long expensive tests and submissions for label changes that do not relate to dosages, instructions for usage, or efficacy claims. Stating a simple chemical fact would be no different than an address change and take no more than 30 days with minimal cost (I checked this with the EPA).crawlejg said:
The manufacturers are intentionally withholding materially important information that consumers need to know to make informed purchase decisions (the definition of fraud, though legally they can claim that they do disclose the ingredients and it's up to consumers to figure out the consequences, perhaps consulting a chemist!) because they don't want you to know the side effects of continued use of their products that can lead to algae growth requiring you to buy algaecides that they also sell at even higher profit margins. They don't completely hide the facts since they do say in product literature that stabilized chlorine adds CYA, but they are not specific as to how much they add even though the following rules are chemical facts independent of concentration of product or of pool/spa water volume:
For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm.
Some simple math shows that even with a low daily chlorine demand of 1 ppm FC, continued use of Trichlor pucks/tabs adds over 100 ppm CYA in 6 months if there is no water dilution. Of course, the stabilized chlorine manufacturers say that CYA is no problem, not even at 100 ppm and that you shouldn't even think about CYA until it gets to at least 200 ppm. They then recommend 1-3 ppm FC (most Chemtura products including BioGuard) or 1-1.5 ppm FC (most Advantis products including GLB) which are woefully inadequate for the higher CYA levels in any pool unlucky enough to have sufficient nutrients for algae. These companies then offer "no-algae guaranteed" programs that include, to no one's surprise, algaecide from those companies and also typically include clarifiers to keep the water clear since the slower oxidation of bather waste can otherwise cloud the water -- another side effect of high CYA without proportionately high FC.
There is no question that Trichlor pucks/tabs are very convenient as slow-dissolving sources of chlorine; an SWG is, of course, even more convenient. There are many pool owners who would just as soon pay more, including use of algaecides and clarifiers, for that convenience. However, as we know from many users on this and other forums, there are many other pool owners who have no problem adding chlorinating liquid or bleach regularly and maintaining their pools at lower cost. It's a cost/convenience trade-off that consumers should be able to make with a full disclosure of facts.
Richard
It certainly is. More good reasons to find a good resource such as TFP to learn to take care of things on your ownchem geek said:
For us, the TFP way is both cheaper and more convenient. It sure beats running to the pool store to buy Crud we really don't need that will never solve the problem.
The pool is finally coming around. Unfortunately, my vacation is over with no swim time. The pool is still a little cloudy, but vastly improved. I can see the design on the vinyl floor down to about 5-6' deep. I'm getting ready to add some bleach for the first time in several days. I have managed to replace enough water over the past few days to lower my CYA to 65. That should be manageable for now and will improve with splash-outs and backwashing as the season heats up. 
Below are my most recent results:
FC: 1.8
CC: 0.2 (or less, it was a single drop)
pH: 7.0 (low, but my alkalinity is high, so I am attempting to aerate to lower it)
TA: 275
CH: 310
CYA: 65
The pool is still a little cloudy, but vastly improved. I can see the design on the vinyl floor down to about 5-6' deep. I'm getting ready to add some bleach for the first time in several days. I have managed to replace enough water over the past few days to lower my CYA to 65. That should be manageable for now and will improve with splash-outs and backwashing as the season heats up. Below are my most recent results:FC: 1.8
CC: 0.2 (or less, it was a single drop)
pH: 7.0 (low, but my alkalinity is high, so I am attempting to aerate to lower it)
TA: 275
CH: 310
CYA: 65
Yes, indeed! I added two large (182 oz) jugs of 6% chlorine bleach, which according to the pool calculator should bring me up to around 7 ppm FC. Thanks again for all of your help!frustratedpoolmom said:You did raise the FC, correct?