Trying to get chlorine pool blue

rawman

Member
Oct 17, 2021
5
Mobile, AL
Hi,

I am new to pool ownership. My pool is green. It is approximately 40,000 gallons.
While awaiting the arrival of my Taylor K-2006C kit, I went to a pool store.
The chemistry:
FC: 0.02
CC: 0
pH: 8.7
TA: 35
CH: 278
CYA: 6

I have muriatic acid and chlorinating liquid and can purchase any other needed chemicals. Thank you for any assistance.
 

YippeeSkippy

Mod Squad
Gold Supporter
LifeTime Supporter
Jan 17, 2012
17,711
Evans, Georgia
Hi there Rawman.... is your pool plaster, vinyl lined, or fiberglass?

What chemicals have you added to the water up to this point? How have you been sanitizing up till now?

We can't act on those test results because they're inaccurate (for reasons too wordy to get into now) so I would just suggest that untill your new test kit arrives you should add a gallon of Liquid Chlorine into the water and brush the pool real good. Do this daily then once your kit comes you will run all the tests and report them so-
FC
CC
pH
TA
CH
CYA
Salt if applicable

Can you do this?

Maddie 🐞
 

HermanTX

Gold Supporter
May 20, 2020
2,753
Katy TX
Pool Size
14600
Surface
Plaster
Chlorine
Liquid Chlorine
@rawman It would be helpful as well to go to your Signature (look under Settings) and update that with key information about the type and size of pool, your equipment list and any water features you may have. This avoids you having to repeat that info each time you post a question. Liquid Chlorine (LC) is all you need to resolve an algae issue. You can buy 10% LC at Home Depot.
 

rawman

Member
Oct 17, 2021
5
Mobile, AL
1. How do people measure liquid (primarily muriatic acid) from a gallon bottle? There are no marks on the bottles to gauge the amount.
2. I read that you should not backwash after adding CYA, but the pressure increased and there is visible particles in the water. It seems that there is no other option. How do people clean algae out and SLAM without backwashing?
3. Is there a particular order that may be more efficient to correct the values (pH, TA, CYA, FC)? I would imagine if the CYA is correct prior to the FC, then the pool might lose less chlorine.

I have the Taylor K-2006C kit, but there are limits to the CYA and pH.
4. CYA - The lowest level of CYA that I can measure is 30, but the levels are less than that. How does one accurately measure low levels of CYA? Is it possible to use 10% of the water and then divide the result by 10.
5. pH - The highest that I can measure is 8.0, but the pH is higher than that. How does one accurately measure high pH?
 

PoolStored

Gold Supporter
Jun 24, 2021
564
Ashtabula, OH
Pool Size
31000
Surface
Vinyl
Chlorine
Liquid Chlorine
1. How do people measure liquid (primarily muriatic acid) from a gallon bottle? There are no marks on the bottles to gauge the amount.
Use a plastic measuring cup. Use one for chlorine, and a different one for MA (this is for safety...never mix them). Some of us that have become one with our pool, eyeball it.
2. I read that you should not backwash after adding CYA, but the pressure increased and there is visible particles in the water. It seems that there is no other option. How do people clean algae out and SLAM without backwashing?
I got a lot of my algae out with a dolphin. you can backwash after adding CYA, just wait 24 hours for it to disolve. the pressure increase is likely something else, unless you dumped a ton of dry cya into your skimmers. You should put dry CYA in a sock and hang in in front of return, or in the skimmer.
3. Is there a particular order that may be more efficient to correct the values (pH, TA, CYA, FC)? I would imagine if the CYA is correct prior to the FC, then the pool might lose less chlorine.
pH first, especially if you have a vinyl liner. CYA and FC can go hand in hand, just raise your FC as you raise CYA. Adding enough LC to maintain 5ppm FC until you get your CYA to target, then adjust target FC for your CYA. TA can be handled as needed to control pH rise.
I have the Taylor K-2006C kit, but there are limits to the CYA and pH.
4. CYA - The lowest level of CYA that I can measure is 30, but the levels are less than that. How does one accurately measure low levels of CYA? Is it possible to use 10% of the water and then divide the result by 10.
You don't. Below 30, just add enough cya to raise 10ppm, wait 24 hours and test again, until it is solidly 30. Then test/add from there to get to target!
5. pH - The highest that I can measure is 8.0, but the pH is higher than that. How does one accurately measure high pH?
You don't. Just like CYA, add enough MA to reduce pH .2, pump/circulate 30 minutes, retest. When you get to 7.8, then you can add MA to accurately get to your target.
 

Phookinl

Active member
Oct 11, 2021
38
NSW Australia
My rule of thumb for a green pool is that the pH is often very high. Most of the tests use pH sensitive dyes, so if the pH is out of the normal range by a long way, pretty much all the other tests become unreliable. If the pool shop are using a colorimetric test then 8.7 may just be the top of the range and the pH can actually be higher. If they use a pH meter the number is usually more reliable, assuming that they look after the meter and probe right.

The chlorine that you add gets less effective as the pH goes up, so getting the pH down is the first order of business. Dumping in a ton of chlorine at pH 8.7 is less effective than adding an appropriate amount of chlorine at the right pH.
 

PoolStored

Gold Supporter
Jun 24, 2021
564
Ashtabula, OH
Pool Size
31000
Surface
Vinyl
Chlorine
Liquid Chlorine
You don't. Below 30, just add enough cya to raise 10ppm, wait 24 hours and test again, until it is solidly 30. Then test/add from there to get to target!
Correcting my answer. It is not necessary to measure below 30. Do as I describe above.

You CAN buy this kit taylor Turbidimetric, 0-500 ppm Test kit, but I don't see the value for $75 for a kit to test below 30, when you want to be above 30 anyway.
 

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Phookinl

Active member
Oct 11, 2021
38
NSW Australia
La Motte make an spectometer called the Waterlink Spin Touch. They have become very popular with pool shops here in australia, they take most of the operator error out of the analysis, although they don't eliminate misinterpretation of the data, bad advice or analytical errors due to the water being out of the normal range for the methods used. The CYA test on these units is actually very reliable as long as your water isn't cloudy. You'll notice in my signature I use a locally made test kit from Clear Choice Labs in conjunction with the Waterlink Spin unit at the pool shop. It's the CYA result I'm using from that instrument. My pool is very full after the off season, so I'm letting the sun evaporate out some water before finalising the water chemistry so I don't overshoot. My last three CYA analyses, which came from two different pool shops were 30 ppm, 29 ppm and 31 ppm. That is perfectly in line with my additions after winter, and I've adjusted it up to 45 ppm and will tweak it a little more to get it to ideal once the water level settles down. As long as the pool water is in the normal range, the instrument gives reasonably good results for all the other parameters too, it is much more consistent than titration methods which require some technique and good lab practices to be reliable. With this unit they just inject about 3 mL of pool water and that is the only operator input. So most of the operator error is eliminated. The turbidimetric method in the Clear Choice Labs kit was still new chemistry when I bought my kit. They had a lot of issues with the stability of the reagents and even after replacing mine, the method was useless. When the test works as intended it is subjective and inaccurate. So I'm happy to go down buy a few liters of acid or some stabiliser and get a free test and a reliable CYA level to work from at the start of the season.
 

Donldson

TFP Expert
LifeTime Supporter
Jun 12, 2009
5,161
NW Ohio
they take most of the operator error out of the analysis
No it doesn't. These devices need regular calibration. Since calibration does not enhance sales it is something that's often overlooked. All that matters is that the results look precise (it cannot measure to 1 ppm CYA, but it will sure try to tell you that) so that customers believe it is accurate. I understand given your background you're probably used to devices being well built and well cared for, but a pool store is not stocking lab-grade equipment and is definitely not holding itself to the same standards of equipment maintenance. It's a sales floor staffed with salespeople working a summer job.

The melamine CYA test is very accurate, despite it's imprecision. Since you are doing it yourself you can trust the results. There is no reason to ever have your water tested at a pool store and it is never recommended here. Do your own testing, trust your own testing. Pool store testing isn't worth the price you pay for it.
 
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an1vrsy

Bronze Supporter
Jul 10, 2018
444
Las Vegas, NV
Surface
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SWG Type
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5. pH - The highest that I can measure is 8.0, but the pH is higher than that. How does one accurately measure high pH?
You have the K-2006C, add R-0005 acid demand. If you’re above the 8.0 on the scale, I would add 2 drops then check. Still above 8, add another 2 drops. If 4 drops of R-0005 brought it down to 7.8, I would look in the Taylor book and see how much ounces of MA the book says to use. THEN I would use Pool Math and look at the effects of adding that much MA would have on my pool. YMMV, that is what I’d do.
 
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Phookinl

Active member
Oct 11, 2021
38
NSW Australia
No it doesn't. These devices need regular calibration. Since calibration does not enhance sales it is something that's often overlooked. All that matters is that the results look precise (it cannot measure to 1 ppm CYA, but it will sure try to tell you that) so that customers believe it is accurate. I understand given your background you're probably used to devices being well built and well cared for, but a pool store is not stocking lab-grade equipment and is definitely not holding itself to the same standards of equipment maintenance. It's a sales floor staffed with salespeople working a summer job.

The melamine CYA test is very accurate, despite it's imprecision. Since you are doing it yourself you can trust the results. There is no reason to ever have your water tested at a pool store and it is never recommended here. Do your own testing, trust your own testing. Pool store testing isn't worth the price you pay for it.
I appreciate that pool shops and their testing have a longstanding and well earned reputation for poor test results and even worse advice. I am very much an advocate for doing your own testing. I agree with that absolutely. Nobody cares about your pool as much as you do.

I have, however, a quarter of a century of experience in water testing in an industrial context, a degree in analytical chemistry and a very good understanding of how these instruments work.
I have spent twenty years teaching sales people (mostly engineers) to do water testing. So I also have a very realistic idea of just how many different ways people can mess this sort of stuff up.

This particular instrument is factory calibrated, and comes supplied with a calibration check disc, to make sure that it is giving consistent results. The light sources are LEDs which do not change and degrade over time with anything like the rate that traditional filament sources and bulbs do. It's not normally user calibrated on a day to day basis, but the check disc should be used regularly to make sure that it doesn't need servicing. Generally if it really is out of calibration, all the results will be badly off so it is pretty obvious although probably not to the average pool shop kid. Secondly, as I mentioned there are many reasons why colorimetric tests can be inaccurate, particularly when the pool water is outside the normal range. This is aside from the issues of poor training, sloppy technique, lousy laboratory hygiene, contaminated reagents, expired reagents and so on. So, please don't take this as any suggestion that people shouldn't do their own testing with a good quality and reliable kit.

The CYA test on these instruments is not a colorimetric test. It is a turbidimetric test and there are no colored dyes involved. The reagent (melamine) forms an insoluble species with CYA resulting in turbidity which is measured by measuring the change in the light level passing through to the detector. (This isn't a true turbidity measurement, which measures scattering rather than transmittance). The change in light transmittance through the disc is very reproducibly measured and the instrument is far more sensitive and far more consistent than the human eye. I haven't seen La Motte make any claims about 1ppm resolution for the method. They certainly only report figures to the nearest whole ppm. Having said that I have used other turbidimetric methods which give excellent accuracy and give 1ppm resolution, and other methods that are 2 ppm resolution, so I wouldn't be at all surprised to see that. It is however more precise and more accurate than visual methods particularly at the lower end of the measurement range.

Over three weeks I got three tests at two different shops and they all came back within 1ppm of the mean. Different sample, different operator, different instruments, same result +/- 1ppm. That result perfectly matched what I added to the pool. That is a very consistent result. There was considerably more variability in the other test results and I'm not suggesting people stop doing their own testing. I'm saying that this instrument, for this method is generally reliable and saves a bit of messing around at the start of the season to get your stabiliser levels adjusted when the concentration may be below the level detectable in the home test kits. My local pool shops don't charge for testing as long as you're buying something, if I'm adding stabiliser anyway, I don't mind buying it from them.
 
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Donldson

TFP Expert
LifeTime Supporter
Jun 12, 2009
5,161
NW Ohio
My local pool shops don't charge for testing
Like I said, it's not worth the price you pay.

I am not going to read your post because it wouldn't change anything. If you'd joined this site with the intent to learn first and instruct second you'd have noticed the mountain of examples of pool store testing of all varieties, digital and otherwise, being inaccurate and inconsistent. You'd either have changed your opinion on the value of the testing or at least realized that recommending it isn't smart advice. That doesn't appear to be the case, unfortunately, and so you're typing long posts about the reliability of pool store testing at the very same time a thread is active showing two pool stores testing the same sample on their digital systems and coming up with impossibly different results. Sorry, I think that's a bit more convincing than anything you have to offer.

Pool store testing is not accepted as a basis to provide advice. It is not recommended that users "confirm" their results against unreliable testing at a pool store. It's led to far more confusion and unnecessary concern than it ever has in finding testing error.
 
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Phookinl

Active member
Oct 11, 2021
38
NSW Australia
Like I said, it's not worth the price you pay.

I am not going to read your post because it wouldn't change anything. If you'd joined this site with the intent to learn first and instruct second you'd have noticed the mountain of examples of pool store testing of all varieties, digital and otherwise, being inaccurate and inconsistent. You'd either have changed your opinion on the value of the testing or at least realized that recommending it isn't smart advice. That doesn't appear to be the case, unfortunately, and so you're typing long posts about the reliability of pool store testing at the very same time a thread is active showing two pool stores testing the same sample on their digital systems and coming up with impossibly different results. Sorry, I think that's a bit more convincing than anything you have to offer.

Pool store testing is not accepted as a basis to provide advice. It is not recommended that users "confirm" their results against unreliable testing at a pool store. It's led to far more confusion and unnecessary concern than it ever has in finding testing error.
:) Feel free to disagree with something you haven't read to your hearts content, mate. I'm not here to criticise the TFP methods, which are all based on sound understanding of the pool water chemistry. If you'd read that last post you'd know that. This isn't helping the OP in any way though so consider it parked.
 

rawman

Member
Oct 17, 2021
5
Mobile, AL
Thank you for the responses. The stepwise approach to getting within the measurement range makes sense.

heikejohn:​

Your idea is very helpful. I need to be able to measure the muriatic acid and made gradations on an orange juice bottle for that purpose.

I have a Polaris. Is that the same as vacuuming? How do you effectively vacuum if you can't see the bottom of the pool?
How do you know that you are getting the sediment?
I stir up some sediment when I am brushing.
I think that the sediment is a huge reason for the cloudiness of the water.
 

Phookinl

Active member
Oct 11, 2021
38
NSW Australia
Sort of kind of. There are two basic types of pool cleaners if you don't include the robots. Some are driven by the suction of the pool filter and others run off a separate pressurised line. I think the Polaris is a pressure cleaner, but that is just how it is driven. Both do much the same thing, in terms of sucking gunk off the bottom of the pool. The difference is that the suction cleaners will usually vacuum the pool via the skimmer box so all the stuff you pick up will either get caught in the skimmer box or go into your filter unless you have the option of diverting the flow to waste. that's usually only an option on sand/media filters.

Where the pressure type are good is that they usually have their own filter bag which captures most of the debris. This is a two edged sword, it cuts both ways. It means that the filter is left to run and capture only the fine material, and the skimmer basket isn't getting clogged with all the dead leaves and coarse material. The down side is that the filter bags aren't always fine enough to capture the very fine material such as dead algal cells. As long as it keeps stirring them up though the filter will eventually take care of them.

When the pool is really dirty, it can be really hard to see what you're doing. You will stir up some material and if you don't have the option to vaccum to waste, you will do a lot of filter cleaning. That's actually OK. The filter will capture any fine material if it's suspended. Whether you manually vacuum or use the polaris, it will work better if the gunk isn't actually sticking to the bottom of the pool, so brushing it does dislodge it but most of it settles again. It's then easier to vaccum up. The polaris is going to eventually cover the whole pool, so happily with that you don't really need to see what you're doing. As the chlorine kicks in the algal cells die and you will start to get a bit more clarity. A big algal bloom can take a lot of work to recover from, and I think for most of us, we would take it as a really good motivator to stay on top of the water testing afterwards.
 
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