Confused on what to fix first!

Hello, I have a 7200 gallon inground gunite pool with a saltwater generator. Current readings are Cl above 5.0, pH above 8.2, and TA about 320. After finding the chlorine level so high I turned off the saltwater generator, then retested a couple of days later with no improvement. I drained half of the water out of the pool and refilled but the chlorine level is still above 5.0. I have added about a gallon of muriatic acid over a couple of days and it doesn't seem to be touching the TA. Should I add sodium thiosulfate to bring the chlorine level down and just keep adding more muriatic acid? Could my cell be bad and therefore causing the generator to make more chlorine than necessary? What do I do next?

OK, first HOW are you testing and what makes you think your chlorine level is "5"? Are you using an OTO kit that only goes to 5? If so, you'll need to dilute your pool water with distilled water to get a true reading. I advocate the "CarlD Shotglass Method". Take one shot of pool water and one shot of steam-distilled water (every supermarket sells it). Voila! Now your reading of "5" is really 10! Or use two shots of distilled to one of pool and your reading of "5" means 15! If your water was actually 15 and is now 10, with an OTO test that only goes to 5 you'd think it's stuck on "5" when it's actually coming down...bet your pool is really clear, though!

Second your pH is 'WAY too high. You need to add some muriatic acid to bring it down (Start with half a cup). When it's in the low 7's you'll see your T/A is lower too.

I think once you can get the TRUE chlorine level, we'll find you aren't as bad off as you thought.

Keep in mind too that if your chlorine is above 10 ppm, it can cause your pH to read high, so I would get the chlorine issue resolved, then retest and adjust the pH.

Janet

Thanks for getting back to me so quick and to answer your first question I am using a basic 5 test kit that only goes up to Cl of 5ppm. My water is crystal clear, just burns the eyes when you swim!

I took a sample of water this morning and tested it myself and used the shot glass method that you recommended and found that my Cl was at 12. My other numbers were pH of 7.8 and TA was at 320 according to my test results. I took a sample to my pool store and their results came up with a Cl reading of 10 or more (their results only go to 10), pH 7.8, TA 165, Hardness of 200 and CYA 100, and TDS of 1200.

I added chlorine neutralizer and the Cl is down to 4, I added muriatic acid and the pH is at 7.2 and the TA according to my test is 260. My question now is why should my TA reading be so different from the reading that they did at the store? I just purchased this kit a month ago so that I could have fresh testing chemicals so it can't be that they are old and my other tests results are right on with the store tests results. Should I purchase a test kit that measures the CYA as mine does not?

Ok, first I want to say I am sooooo glad that I found you guys, people that really know what they are doing. I am ashamed to admit that I have been "pool stored!" But after reading more and more here I think that I am starting to get the picture. I didn't have a test kit to measure CYA so, out-of-site-out-of-mind and now my CYA is 100 and I just brought my Cl from 12 down to 4 not realizing that I needed a higher amount of Cl. So, I vow never to listen to the pool store people again! I now realize that I have so much more to learn.

So, tonight I purchased the Taylor-K006 testing kit by cutting and pasting your affiliate link to Amazon...btw, I couldn't find a regular link for this kit on your site, I didn't know if you're aware of this? But hopefully this will get here soon! The other thing is I wanted to give you the other information on my pool. My pool is a 7200 gallon gunite saltwater pool that is in a screened in pool-house, that maybe gets 4 hours of sunlight to approximately 1/4 of the pool. The pool temp runs between 75-84 F during the summer. I have a Hayward Sandfilter with a Goldline Saltwater generator. I have been running the filter 24/7 for the last two weeks. I am still waiting on an answer to my last post, but I thought the extra information might be of help.

Thanks again, Lisa

Hi Lisa;

"Burning eyes" are a relative thing. Fresh water alone causes eye discomfort, as does sea water. To avoid all "burning eyes" you have to use something equivalent to saline solution, which is MORE salty than a salt chlorinator pool, but LESS salty than the ocean.

So, from the point of view of an experienced pool service guy, a complaint of "burning eyes" is meaningful only if it's comparative, like "It never burned our eyes till a week ago".

So the question is, "Has it always burned your eyes like this, or has something changed?"

Often in my experience, burning eyes -- other than just from staying in the pool a long time, for from fresh, or very salty, water -- are caused by three things.

First, is combined chlorine, from chlorine + too much urine, or chlorine + foamy algaecides, or chlorine + Yellow Out type ammonia based algaecides. In this case, the solution is to keep adding chlorine, stop adding the other stuff, and wait.

Second, some algaecides will cause significant eye irritation all on their own. Again, the solution is to wait.

Third, very low pH will cause eye irritation. (Very high pH could too, but I haven't personally encountered complaints arising from that situation.)


Other issues:

Thanks for the heads up, but I do know about the bad link. Unfortunately, it's turned out that I can't enable those links inside a forum section without turning on HTML within that section for everyone who posts . . . and that's a huge security risk. I'd tried to do it for just me, but wasn't able to find a combination of settings that accomplished that. A solution is a little further down the road.

Also, you do need to test your CYA. As soon as your K2006 arrives, test your pool water for CYA, using a 3:1 dilution (1/4 pool water, 3/4 cup tap water, mix, test, multiply result x4). Your CYA levels may be quite a bit above 100, and that's something we need to know. By the way, do NOT overtest CYA: the K2006 only has enough reagent to test CYA 6x!

Finally, the TA variation is not unusual. Unless you carry your sample to the pool store in a tightly closed bottle AND have filled it so no air space is left in the bottle AND keep it reasonably cool till it's tested, you can see big variations, that are not testing errors. On the other hand, test kits may be bad, and pool stores are often bad. So, don't worry about it, and just wait for the K2006.

Everyone's been "pool-stored" at one time or another--but most of us have had someone on PF point it out to us, rather than pick it up on our own, as you did.

With a CYA of 100, to tell someone to reduce an FC level of 12 to 4 is like telling someone with pneumonia to go skiing! Just not right.

You CAN get refills for the CYA reagent -- Taylor Reagent # 0013, I believe. I keep a pint bottle in a dark, cool cabinet, as well as other refills. But, with care, you'll easily make the end of this season with your new K-2006.

That your water is clear is a really good sign. That means we will get you to adjust chemicals, but you don't have to FIGHT a problem, like algae.

Once we know the true T/A (and the K-2006 will tell you that) we can guide you to lowering it. We'll also know the true FC and CC levels. Your "Shot Glass" measure of 12ppm is for total chlorine (TC) and the "Shot Glass" measure isn't very precise (that's no reflection on you--I use the shot glass because it's very easy to dilute more precisely that way), although it works as an excellent "Plan B" method.

If, what Ben suspects and suggests is true, that your CYA is actually much, much higher than 100, then draining and refilling much of your water will be in order, and that may TOTALLY alter your T/A level as well. We'll cross that bridge when we come to it. Luckily, with a smaller pool, it's less painful to do so.

But please don't just empty the pool and refill it....bad things can happen from doing that, especially if you have a lot of ground water around the pool (it can float, like a boat--very, VERY bad!)