Test results on new pool in Tucson

[Wilco]

So have been in this house for a month, new pool owner. Hard water here in tucson. Monitoring with guess strips, shocking once a week or so. Seemed to have consistently low ph and low chlorine though. Pretty clear overall, use sand shark vacuum regularly, large triton II sand filter, pebble tec Pool
Is 30' x 20'. Added one box of borax to skimmer, tested with spanking new Taylor kit:
Ph 7.9
tA. 90
CH 380
Cya 110
Free cl o.6
Comp cl 0.6
Sat index 0.6

Water seems good, clear. Anything I should worry about? Thanks.

.

[Watermom]

What are you using as your source of chlorine? Your chlorine is WAY too low for a pool with a CYA of 110. (How did you get a reading of 110, anyways? The kit only goes to 100.) If your pool is clear, you are very lucky. You have the perfect conditions for an algae bloom --- low chlorine and high CYA.

With your CYA, you need to be keeping your chlorine between 8-15 ALL the time. And, when you need to shock, your shock level will be 25ppm.

Have you been shocking weekly and then adding no additional chlorine until it is time to shock again? If that is the case, there is a better way to do things. It is best to test every day or two and add enough chlorine to get back to around 15ppm. You want to be able to never drop below 8ppm. You may find that you can go for several days between doses of chlorine depending on how fast your chlorine level drops.
More about the CYA and chlorine connection can be found here:> http://pool9.net/cl-cya/

Your CH and CYA are both high enough. Therefore, it would be best not to use any cal-hypo or any forms of chlorine that have CYA in them such as trichlor pucks or dichlor shock powder. Instead, just use bleach. Many of us use Walmart's generic 8.25% bleach as our source of chlorine. If you tell us the volume, we can calculate a dose reference for you.

Hope this helps. Repost with the answers to the questions and someone here can help you go from there.

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[CarlD]

Hi and welcome!

Just to add to WM's advice: Don't use the 25ml line for your testing of chlorine (FC and CC). Instead use the 10ml line. That way, each drop of the R-0871 liquid will equal .5ppm of FC or CC, and 2 drops = 1ppm. Whereas, with the 25ml line you need 5 drops for every 1ppm--and that uses up your reagent liquid. Measuring to .5 rather than .2 is 'WAY good enough for everything we do here.

[Wilco]

Thank you, I was hoping to get an answer like that and convert to bleach. Initial pool inspection guy set me up with the tricolor pucks, and I've had 4 in a floater consistently, and have shocked with 2 bags of shock 4 times in a month. I think that my hard water is preventing good chlorine saturation. Will the bleach work better? Also, I estimated the cya, as it was just above 100.

[Watermom]

The bleach will not add unwanted things along with the chlorine. If you give the volume of the pool, we can help you determine doses of bleach to add.

[Wilco]

It's about 18000 gallons, spa is 500. Again, I think the excessively hard water here is the X factor. What unwanted additives do the tricolor pucks and dichlorvos shocks add?

[Watermom]

Trichlor and dichlor both add CYA and yours is already too high. For reference --- each quart of 8.25% bleach will add around 1ppm of chlorine and each of the 121-oz jugs will add about 4.5ppm.

[Wilco]

Excellent, thank you. Now what to do with sell the pucks I will have lying around.........

[CarlD]

If you can keep them, in the spring your CYA may well be lower--very common. If not, give them away if you can.

Tri-chlor pucks are GREAT when you have a high pH and low CYA situation as they are very acidic and add 6ppm of CYA for every 10ppm of chlorine.

[Wilco]

Hit it with 4 qts of bleach. Waiting to retest. Any guesses?

.

[CarlD]

Why guess? That's why we test.

[Wilco]

Ok.didnt budge the chlorine level, but brought the cya down to about 40. Smells more chloriney

[Watermom]

Adding bleach cannot drop the CYA level. It would probably be a good idea to watch these testing demo videos:> http://pool9.net/K2006-vid/ and then try your tests again.

[Wilco]

Maybe apples and oranges, second test was with 6 way strip. Will do full Taylor tomorrow I guess

[CarlD]

6 Way strips do NOT give a good CYA reading. The color in the very center MAY be correct if you're super-careful, but the color of most of the pad usually isn't.

[Wilco]

Ok.test strip (6 way) foes seem yo consistently show cya of 40-60, while the kit shows about 100. Have hit it w bleach and had cl up to 6 and ph at 7.2. How aften do I need to add bleach generally to keep from porpoising?

[PoolDoc]

=> CH=380 is not really a problem; just run your TA lower. (http://pool9.net/alk-step/

=> With a high CYA, consider establishing a borate level > 60 ppm. The primary downside of a high CYA is that IF you get algae, it can take extreme levels of chlorine to eradicate it. Adding borates doesn't kill algae, but it does make your pool less susceptible. http://pool9.net/borates/

=> As mentioned, it IS typical to lose CYA over the winter. But you probably want to avoid this. Bacterial decomposition is the reason for this loss, and it can have hard to predict effects. Most often, the CYA is converted to nitrogen gas (no problem!) or nitrates (minor problem). But in a significant percentage of cases, the conversion is to ammonia, which is a big problem, and tends to ruin your spring start up.

=> In Tucson, I'm guessing you plan to run the pool all winter, and leave it uncovered. I'd highly recommend keeping 4 gallons of bleach on hand (stored in a cool place), and dumping all 4 gallons into your pool at the FIRST sign of algae or biofilm.

Good luck!

[Wilco]

Ok. Just retested and can't even detect cl levels, and ph down to 7.0. Seems like I will have to pour a gallon of bleach in a day at this rate. Where is all the cl going???

[PoolDoc]

1. Did you use OTO drops to test?

2. What time of day did you test?

3. Regardless: add 2 gallons of bleach in the LATE evening and then test with OTO the following EARLY morning.

4. Post dimensions (shape, max length, max width, shallow depth, deep depth) AND reported gallons.

[Wilco]

Yes I used the Taylor kit for test. I then added a box of borax and one bag of shock. Retested an hr later at 4 pm and got ph of 7.2 and cl of 4 ppm. Just seems like cl disappears.

[Wilco]

Pool is 32' x 13', sort of curved rectangle/trapezoid. 3' shallow to 10' deep. 18000 gallon I think with 500 gallon spa attached.

[FormerBromineUser]

What is your K2006 CYA reading? If 100, your actual CYA may be higher. If 100, try a dilution test to determine your actual level. Mix 1/2 cup distilled water with 1/2 cup pool water, and run the CYA test again. Multiply the result x2. Post your results, please.

[Wilco]

The cya tests between 90 and 110, given how the drop test is a little fuzzy

[PoolDoc]

Yes I used the Taylor kit for test.

*Which* Taylor kit?

If you have a DPD color match (K2005, etc) those are USELESS for diagnosing "no chlorine" problems. If you have a K2006, do the overnight bleach test, but test with BOTH the K2006 *and* an OTO drops kit. If you do NOT have the K2006 (or K1515) use only the OTO kit.

But . . . use an OTO kit no matter what!

[Wilco]

I have the 2006, I don't have an oto kit. Sounds like it's better for routine cl testing/management.?

[Watermom]

An OTO/Phenol Red kit (yellow and red drops) is useful for quick daily checks. It is what I use most days and then use the K2006 once a week or so. An exception is of course, if I have need to shock the pool and need to be able to test higher than 5ppm of chlorine. In that case, the K2006 is needed.

[PoolDoc]

OTO is not super accurate, but it covers the range from 0 - 50 ppm, and it's pretty much goof proof. The FAS-DPD test covers the same range, but it *can* be screwed up. The DPD color match (K2005) covers the range from 0 - 5 ppm, (0 - 10 ppm claimed, but few people can read the difference between a 5 ppm red and a 10 ppm red!) and there are multiple ways it can go wrong.

[Wilco]

Good help, thx. Tested with kit (Taylor) after gallon of bleach last night and borax the day before. Now at 7.4-7.6 and cl is 5 ppm on Taylor, although correlates at 1-2 ppm on strip. Think I'm ok for a bit, but will get oto kit for use as well.

[PoolDoc]

If chlorine levels hold overnight, but disappear during the day . . . your CYA is low. If your CYA testing is not indicating this, please watch the CYA test videos linked from the testkit page: http://pool9.net/tk/

[Wilco]

My cya has consistently tested high, like 100. That is consistent with the history of previous owners using trichlor tabs exclusively. I thinkits more a product of the super hard water here not allowing chlorine to stay free. (?)

[CarlD]

No, it's a product of using TriChlor tablets that release 6ppm of CYA for every 10ppm of chlorine. That's why your CYA always tests high. Nothing to do with hard water at all.

[Wilco]

Ok, but the tabs aren't keeping the cl level up at all. So I quit and went with Bbb method. ( although haven't added the third b yet, not sur when to. TA stays about 80.

[FormerBromineUser]

Please: Read all you can here http://http://poolsolutions.com/gd/the-BBB-method-of-swimming-pool-care.html
Then, throw away the test strips, hide the Tri-Chlor pucks somewhere cool, and then follow PoolDoc's advice. Keep your FC over at least 8 until you KNOW your CYA level for sure.

[PoolDoc]

+ As far as I know, hardness has NO effect on chlorine levels . . . or loss.

+ Trichlor will maintain chlorine levels just fine . . . IF you dissolve it. But undissolved trichlor has NO effect on chlorine levels. Also, I believe some 'diluted' trichlor tabs are now being sold.

+ Fully dissolving TWO complete tabs of 89% chlorine trichlor tabs is approximately equivalent to adding 1 gallon of 8% bleach, except that the tabs ALSO add CYA and acidity.

[CarlD]

Ok, but the tabs aren't keeping the cl level up at all. So I quit and went with Bbb method. ( although haven't added the third b yet, not sur when to. TA stays about 80.

The BBB method is a method, a philosophy, if you will, of only adding what you need, knowing what you need because you test regularly, and not being taken in by pool chem companies' flashy names so they can charge 3x as much for baking soda or washing soda, or "cocktails" of combinations of chemicals which are more a problem. It's not a rigid system--just the opposite. But you don't add stuff "just in case".

I use Tri-Chlor tabs from time to time--usually in the spring in a floater or two when my CYA is low. I also use Liquid Chlorine instead of bleach because....when I do the math, for me it's cheaper. LC is merely stronger bleach anyway. Mostly though, I use my SWCG for chlorine.
Borax is one of 3 ways to raise pH. But it's generally the preferred way.
Baking Soda is when you need to raise TA. I, and others, have found that TA is only a concern when something else is happening. So if your pH is trending down all the time (and it's not from constant Tri-chlor tablet acidity) raising TA can slow it. A constantly rising pH can be slowed by a lower TA, etc.

[Wilco]

So what do you mean by saying that the trichlor may not be dissolving? I was putting 4 pucks in the floater and they would last a week or so, but I had to add 2 bags do shock in order to notice any testable cl levels. And, as you said, my ph was staying low. Better now using bleach and regular testing. Would using the pucks be am option say if I were going on vacation for a week?

[PoolDoc]

4 pucks per week equivalent to 1.5 lbs Cl2 gas
PF=6.7 for 18k gal pool

So 1.5 x 6.7 = 10 ppm chlorine per week.

Typical daily use, on a lightly used pool in a sunny area, when everything is running well is 1.5 - 2 ppm per day. 10 ppm is at the bottom end of that.

IF there is ANY algae, or ANY problems, chlorine use will be more on the order of 4 - 5 ppm per day OR HIGHER. Cleaning up algae can consume 100 ppm of chlorine in just a few days.

You need to MAINTAIN a chlorine level of 10 ppm (based on your CYA), doing what ever is required to get there. Once the pool is spic and span, you may find that 4 tabs per week (or 2 gallons of bleach) may be adequate to keep it there. But that's not the case, yet.

[Wilco]

Ok, that was what I was getting to, was the daily demand/loss do cl that could be expected. There was an algae bloom when we first moved in 6 weeks ago, but that cleared up with initial treatment. Water has gained clarity steadily, and looks great now, but maybe the residual of that bloom and the heat here increased the demand quite a bit. Are the hth shocks ( sodium hypochlorite) better for me with presumed high cya than dichlor?

[Watermom]

Check the label again. I don't think the HTH shock is sodium hypo. Maybe calcium hypo?

[Wilco]

Yep, calcium hypochlorite, you are correct.

[FormerBromineUser]

Oh my. You want a minimum 10 ppm FC (free chlorine) in your pool. You have Tri-Chlor pucks. They add FC but also add CYA and you don't want more CYA. You mentioned Di-Chlor, same thing. HTH shock adds FC but also adds calcium and your CH is high enough. You have used bleach (sodium hypochlorite), which will add FC but not affect CH or CYA. Is there any particular reason you prefer not to continue using bleach?

[Wilco]

At this point it seems that I will be pouring a gallon of bleach into my pool EVERY day. That doesn't seem feasible, but you are correct in exposing my faulty logic.

[FormerBromineUser]

Wilco, I hope you don't think I was hollering at you. I work with school kids and tend to "teach" in most things I do.

You just want to make your pool better and to use the BBB method; that's great! BUT it can be overwhelming at first. The time and energy it will take now to learn about pool chemistry will be greatly rewarded. You will become more than a pool owner; you will become a pool OPERATOR. The freedom and the sense of accomplishment, pride, and control you will gain is your gift from PoolDoc. Accept this gift.

Here is what I humbly suggest you do:
1) Conduct all testing below using ONLY your K2006
2) Add bleach to get your FC to at a minimum of 10ppm
3) Perform an overnight chlorine loss test. ASK if you don't know how to do this.
4) Report your results clearly on this thread
5) Do nothing other than maintain FC >=10ppm until you receive a response
6) Do not bring up any other side issues in the meantime.

Others who are more knowledgeable than I may disagree and if so, I hope they speak up, but I believe we need to get back to figuring out why you are not able to maintain your FC with reasonable quantities of bleach.

[Wilco]

As long as someone sticks with me, I'd like to do that. FCL was 1ppm this am, added another gallon of bleach.

[Wilco]

Retested an hr later, up to 7ppm. So seems to be correct that I can get 6ppm per gallon of bleach. I added another half gallon, will retest this evening. I searched some older posts on here regarding hard water, high cya pools here in az. Saw some recommendations for pool chlor company, who apparently use cl gas once a week? And possibly a calcium chelator? Wondering how many people have had to go to this and if it is an option. I'd rather do it myself overall, but time becomes an issue at some point.

[PoolDoc]

Essentially, FBU is right: you need to get your chlorine up, and keep it there for awhile, and THEN see if you still have a problem.

We encounter many 'mystery' problems that go away once users do just that. Usually, the problem is resolved fairly quickly that way; sometimes it takes weeks rather than days.

Unfortunately, we often don't know why.

The level of chemical analysis that would exactly answer the "What?" and "Why?" question is almost always out of reach, not only for the pool owner, but also for us. So we have to be satisfied with solving the problem, without necessarily understanding its orign.

[Wilco]

I'm in health care, same deal a lot of the time. Seems like I have a good plan now, will roll with it and keep updating. Thanks

[Wilco]

Hope the kids hair doesn't turn green as well

[FormerBromineUser]

.
Wilco,

1) As long as people feel that you are listening to their advice, there will be someone "sticking with you". Members here like to help. No worries!

2) I neglected to mention in my instructions that you need to keep monitoring your pH and adjust as needed.

3) As for bringing up CL gas/calcium chelators, etc.: Worry now about getting your pool safe-and-sanitary and holding FC. When this is done, then you can explore and discuss alternatives all you want.

4) Green hair? That's a whole different topic which we can discuss in the future. Let's not go there at this point lest this thread get lost in ANOTHER side issue. For now, know that bleach does NOT cause green hair.

[Wilco]

Retested 8 hrs later, upper 90's here today. FCl down to 4ppm.