Low Chlorine Problems

OK I'll start by saying I'm a newbie. I'm not sure how many details I can give, or should give, but here we go.

I told my mother-inlaw I would try to be her pool boy this spring, as she is gone a lot, so I have been trying to learn from your website for the last couple months off & on.

She spent lots of $ dumping in whatever the local pool guy told her over the past 20 years. I have been trying to convince her the BBB method will save her $ & have a nicer, easier to maintain pool. It has worked pretty good up until recently, I can't seem to keep the chlorine levels up & now have an algae problem.

The pool is a 16,000 gal. in ground fiberglass pool, it has a chlorinator, she has been using for years, so the CYA is high, over 100, have gotten mixed readings from the local dealer, ranging from 107-168. He says his machine won't give a accurate reading if the chlorine level is above 3, well from my reading, I have been trying to keep it around 8.

I shut off the chlorinator early on, to save $ on sticks & stop raising the CYA, but the last week have put in 4 gallons of bleach & TC still below 1. The mother-inlaw dumped in a couple bags of shock last night. Will see if that helps? Or was the right choice?

But she just did it & told me later, because I haven't been being a good enough pool boy.

LoL Help Please

I'll try to look at this again tomorrow but it's getting late, so I'll post some relevant snippets that will help get you started.

Ben

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+ Get a cheap OTO (yellow drops) / phenol test kit, or if available at YOUR Walmart (check availability), get the HTH 6-way DROPS test kit, which is compatible with the Taylor K2006. Test the pool as soon and you can, and post the results. If you get the 6-way kit, ALSO test the water you FILL the pool with, especially if it's a well, and post THOSE results as well. (The HTH is the best available kit you're likely to find locally, but it's not the K-2006. It can only provide rough measurements chlorine levels above 5 ppm, and it measures "TOTAL" hardness, rather than "CALCIUM" hardness, which is not ideal.)

+ Having a good test kit makes pool care easier for EVERYONE. A good test kit means a kit that can test chlorine from 0 - 25 ppm, pH, alkalinity, calcium hardness, and stabilizer with reasonable accuracy. Test strips (AKA 'guess-strips' ) do NOT meet this standard. Some pool store testing is accurate; most is not. The ONLY way you'll know whether your pool store is accurate or bogus, is by testing accurately your own self. On the other hand, pool store 'computer' dosing recommendations are NEVER trustworthy -- ignore them. They are designed to sell more chemicals than you need, and WILL cause many pool problems.

+ We recommend the Taylor K-2006 test kit, which meets the requirements above, for many reasons. The HTH 6-way drops kit is a great starter kit, and is compatible with the K2006 (it's made by Taylor). There are a few alternatives; for example Lamotte makes an FAS-DPD kit that's OK -- but it costs 3x as much. But, we're not aware of any test that is better, and since we are all familiar with the K-2006 (and can help you with it) we recommend it exclusively ( Test kit info page )

One caution for the 2012 season: Amazon does not stock the kits directly. So when buying at Amazon, Amato is our current preferred seller. However, they often don't list enough stock to last the whole day, so try order mid-morning. You should expect a delivered cost under $60 for the K2006A and under $95 for the K2006C. If you can't find that, wait a day.

+ Here are links to the kits we recommend (you can check local availability on the HTH kit, using the Walmart link):

HTH 6-Way Test Kit @ Walmart
Taylor K2006A (3/4 oz bottles) @ Amazon
Taylor K2006C (2 oz bottles) @ Amazon

+ It's much easier to answer your questions, when we have the details about your pool in one place. We often 'waste' the first few posts back and forth collecting information. So, please complete our new Pool Chart form -- it takes about 30 seconds, but will save much more than that.

Pool Chart Entry Form

Thanks for the reply, I read more today & expected your answer to be lots of chlorine. I did try to fill out the pool info. Under my ID if it took? The pool readings this evening are:
Fcl:2.5
Tcl:3.13
PH:7.2
Alk:170
CYA:High- too high for my reader 125+
Pool store says total hardness around 300

From looking at the best guess chart I'm guessing I need to have my Fcl around 2525 to shock effectively. I added 1/2 box borax & 3 Gallons 6% Cl. Will recheck tomorrow, & try to keep Cl up that high. I can't test real effectively that high without having to dilute & multiply.

Thanks again

Readings this morning:
Fcl:4.54
Tcl:5.62
PH:7.3
Alk:182

Added another 1/2 box borax & 3 more Gallons of 6% Walmart bleach
People look at you funny when you stroll through the store with 12 gallons of bleach & 3 boxes of borax in your cart. Either I'm a serious laundry man, or making some kind of terrorist concoctions :)

You really need to bite the bullet and order a good kit --- Taylor K-2006. With a CYA level that is through the roof like yours, you will have to run extremely high chlorine levels (per the Best Guess Chlorine Chart in Ben's sig above). The HTH 6-Way kit and an OTO kit only measure chlorine to 5 and aren't going to help you.

You did the right thing turning off the chlorinator but you are not adding big enough doses of bleach to accomplish anything since the CYA is so high. In your pool, each gallon (4 qts.) of 6% bleach will add just under 4ppm of chlorine. As you can see from the Best Guess Chart, your shock level is going to be around 25ppm, so the 3 gallons you added is not taking it high enough. Keep adding bleach every time you test and get back to 25ppm. Continue to do so until you can go from sundown one evening to within 2 hours of sunrise the next morning without losing more than 1ppm of chlorine and the water is clear. Then, keep it high for one additional day. After that, you can let the chlorine drift down but must always keep it between 8-15 ALL the time or you'll constantly be fighting algae. No more trichlor pucks nor any type of dichlor shock powder in this pool!

Your pH is fine where it is so don't worry about more Borax at this point.

Order the good kit. In this pool, it really isn't an optional item but a critical one or else you'll have a very difficult time managing this pool.

Hope this helps. Good luck.

Quote:

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Originally Posted by nscclukas

People look at you funny when you stroll through the store with 12 gallons of bleach & 3 boxes of borax in your cart. Either I'm a serious laundry man, or making some kind of terrorist concoctions :)

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My wife just cracked up, when I read this to her. (She's helping with some forum stuff right now, and is in the office with me.) She -- having been sent to the store on a MISSION by me -- commented, "He should try checking out when you bought the entire stock of 24 boxes of borax from a single store!" :puzzle:

Maybe I'm wrong? But I was thinking on 16,000 gallon pool 1 gallon Cl would raise 8ppm. We just recently bought the Lamotte Color Q 7 digital test kit. It is a liquid test kit, works great, no more guessing at colors, it gives you a # to go by. The mother in-law loves it, she didn't bother to check her readings before very often because it was always a guess what the color was. She just took samples to town & let the pool store tell her what she needed. For 20+ years, imagine how much $ she dumped into the pool. The local pool store will probably go out of business now that I've banned her from going there :)

One gallon of 6% bleach in this pool would add about 3.8ppm of chlorine.

I'm not familiar with that kit or how high of chlorine readings it can read so I can't comment on that. Someone else may know more about its capabilities and limitations.

Not sure if this should be under chlorine or algae?

I'm still fighting to get my chlorine levels to stay high. It's a real battle, been checking 3 times a day & making slow progress. I have put in 20 gallons of 6% bleach, after filling the trash can with empty bottles, I decided to go to Menards & get the 15% LC, & have put in 10 gallons of that, thus far.

This morning readings:
Fcl:3.57
Tcl:6.8
PH:7.1

Any ideas on how to kill this algae? I have scrubbed last two evenings Should I vacuum? Can't see the bottom of the pool, 3 feet at best. I have had it on filter continuously. How about backwashing? I have a couple times for a couple minutes, do I need to backwash till foamy bubbles are done? Pressure hasn't been high on gauge. Just wondering if I'm doing things right?

If you want to know how much more chlorine it will take, you can get an estimate by doing a chlorine demand test:

Bucket-testing-for-chlorine-demand

But do NOT back off while you are checking: with algae, either YOU are winning, or THE ALGAE is winning. There is no 'coasting'; when you coast for a day or two, the algae will recover, and you are likely to lose 100% of any ground you've gained!

By the way, you NEED TO GET A TESTKIT. Your FC=3.57 ppm result tells me you are using a somewhat bogus digital reader, which in turn tells me, that you don't know -- reliably -- what's in your pool

[CORRECTION from ORIGINAL VERSION: The Lamotte Color Q is considerably better than the digital strip readers, which also produce 2 decimal point results. But the evidence still is that the unit's fundamental accuracy comes nowhere close to 2 decimal points, and does not approach the accuracy of titration methods, like the Taylor K200x series. In addition, there's an intrinsic problem with colorimetric methods for calcium and alkalinity: such methods are inherently logarithmic in progression, rather than linear like titration. Thus, color methods become more and more imprecise as the value increases. So the Color Q may be MORE precise than the K2006 for FC=0.1, but MUCH less precise for FC=10 or CH = 400. Unfortunately, this decreasing precision is masked the digital conversion process, which pump out multi-decimal results, even when the unit can barely distinguish 400 ppm CH from 500 ppm CH!]

Please go get a cheap OTO kit, if nothing else . . . and then dose with bleach till you reach DARK yellow, or orange-tinted yellow.

Ben

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+ Get a cheap OTO (yellow drops) / phenol test kit, or if available at YOUR Walmart (check availability), get the HTH 6-way DROPS test kit, which is compatible with the Taylor K2006. Test the pool as soon and you can, and post the results. If you get the 6-way kit, ALSO test the water you FILL the pool with, especially if it's a well, and post THOSE results as well. (The HTH is the best available kit you're likely to find locally, but it's not the K-2006. It can only provide rough measurements chlorine levels above 5 ppm, and it measures "TOTAL" hardness, rather than "CALCIUM" hardness, which is not ideal.)

+ Having a good test kit makes pool care easier for EVERYONE. A good test kit means a kit that can test chlorine from 0 - 25 ppm, pH, alkalinity, calcium hardness, and stabilizer with reasonable accuracy. Test strips (AKA 'guess-strips' ) do NOT meet this standard. Some pool store testing is accurate; most is not. The ONLY way you'll know whether your pool store is accurate or bogus, is by testing accurately your own self. On the other hand, pool store 'computer' dosing recommendations are NEVER trustworthy -- ignore them. They are designed to sell more chemicals than you need, and WILL cause many pool problems.

+ We recommend the Taylor K-2006 test kit, which meets the requirements above, for many reasons. The HTH 6-way drops kit is a great starter kit, and is compatible with the K2006 (it's made by Taylor). There are a few alternatives; for example Lamotte makes an FAS-DPD kit that's OK -- but it costs 3x as much. But, we're not aware of any test that is better, and since we are all familiar with the K-2006 (and can help you with it) we recommend it exclusively ( Test kit info page )

One caution for the 2012 season: Amazon does not stock the kits directly. So when buying at Amazon, Amato is our current preferred seller. However, they often don't list enough stock to last the whole day, so try order mid-morning. You should expect a delivered cost under $60 for the K2006A and under $95 for the K2006C. If you can't find that, wait a day.

+ Here are links to the kits we recommend (you can check local availability on the HTH kit, using the Walmart link):

HTH 6-Way Test Kit @ Walmart
Taylor K2006A (3/4 oz bottles) @ Amazon
Taylor K2006C (2 oz bottles) @ Amazon

Ben,
Although I know nothing about them -- maybe you do --- this member has a Lamotte Color Q 7 digital test kit.

nscclukas,
The pH of 6.8 is too low. You should use some 20 Mule Team Borax (laundry aisle at Walmart) to bump it up to between 7.2-7.8.

Noted and corrected. Thanks WM.

(The Color Q *is* substantially better than strip readers, but still is a colorimetric method, and thus much less accurate than the 3 or 4 decimal point results imply.)

I got my old test kit out to double check the #'s & they are right.
This evening:
Fcl:1.5
Tcl:2.92
PH:7.1
I added 3 gallons of the 15%LC this morning & it's all but gone apparently. I'm. going to add 4 gallons of the LC & a box of borax, scrub & keep after it I guess. I was just wondering if I needed to do anything more or different? Thanks

We really need a CYA reading to be able to advise you. Does your kit test for CYA ?

Tell me if this sounds right? I added the 4 gallons of 15% LC, scrubbed & vacuumed, thought I'd check the Cl before calling it a night, say 2 hours later.
Fcl:4 Tcl:5.6 Can the algae be eating up that much Cl? Or do I have old weak bleach & that's why I can't get ahead?

Quote:

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Originally Posted by nscclukas

Can the algae be eating up that much Cl?

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In a word, yes. Keep hammering it with bleach. We really aren't going to be advise you too well without a CYA reading. That is a critical value to know when you are trying to clean up an algae bloom.

Yes weak Cl? Or, Yes the algae can consume that much Cl?

My first couple posts I explained my CYA is high 125+ my tester only goes that high. I could dilute &multiply multiply if necessary, but I'm pretty sure it's below 200.

The local pool company said my CYA was168 about 6 weeks ago, but he said he couldn't give me accurate readings because I was keeping the Cl level too high at 8. He insisted that I shouldn't have the Cl over 3, said it wasn't safe for swimming & I a waste of $. I tried to explain to him that as CYA levels rise, the need for higher Cl levels, but he disagreed, said he's be doing pools for 30 years & knows better. I said, well of course, you make most your $ selling shock, algaecide, & other unnecessary stuff, not off of helping customers maintain a good clean healthy pools.

So, needless to say, he wasn't very happy with me.

Quote:

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Originally Posted by nscclukas

I added 3 gallons of the 15%LC this morning & it's all but gone apparently. I'm. going to add 4 gallons of the LC & a box of borax,

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Just found out this morning that many SCP distribution locations buy boxed jugs of "liquid chlorine" by the truckload in the SPRING, and let them sit all summer. At this point in time, most of those jugs are probably 1/2 strength or less! In Nebraska, it's not likely you're getting fresh bleach from a pool store that gets weekly deliveries. What's more likely is that what you are buying is some small fraction of its original strength.

That makes sense, it's hard to calculate how much Cl to add when you don't know the strength. I found a great website today, all you will probably want to know about Cl & then some:
[ DELETED BY ADMIN -- SEE EXPLANATION BELOW ]

They explain that Liquid Cl "LC" from the manufacturer is 15%, but in two weeks it's strength is 12.5%, & in 30 days down to 9% strength. So if it was from the spring it's probably no stronger than the recently stocked Walmart 6% bleach. The good news from dumping all this liquid Cl in my pool is it has effectively lowered my CYA. It is now reading 78 :) I'm guessing because of the high Cl demand from the algae, the CYA is bonding with all the liquid Cl I have been adding, which is being consumed by the algae? Still not cleared up, but making slow progress.

Another interesting point made in the article:
[ Mis-information deleted ]

Sorry, Nscc;

The point about the deterioration of high strength bleach, when stored at high temps, is generally valid even if the numbers aren't as simple as they make it. It's a point I often make myself.

But, the rest of the article is a mis-mash of half-truths and out-right errors, some of which are deliberate, at least on the part of the original writers.

If you want to repost in the "China Shop" and debate the details there, you may. But I don't allow that sort of bogus information in the general sections.

I wrote a longer post, but then realized that you probably posted this innocently, and had no idea how bogus the material on that page was.

Good luck with your pool!

OK Thanks...I will continue reading & learning. The chemistry involved in all of this gets way over my head. I really appreciate you being willing to share your wealth of knowledge with all of us. I'm surprised you don't get fed up with having to answer the same questions day after day, year after year. Thanks

Quote:

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Originally Posted by nscclukas

I'm surprised you don't get fed up with having to answer the same questions day after day, year after year.

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Well, one of the great benefits of working with people this way, is that they can't see when I'm rolling my eyes. ;)

Good answer, Ben. That made me laugh!