Alternate chlorination

[dalehileman]

Thread "Trichlor Tabs" discusses the apparent destructive effects of local concentrations, prompting one to wonder why the Pool Establishment hadn't abandoned the method long ago

trichlor-tabs-t16126.html

In the meantime however I had been made aware of a possible alternative that avoids the problem of these local concentrations, using sodium dichloro-s-triazinetrione called "pool shock" and supplied in powder form which dissolves quickly and completely for a uniform distribution. Athough not specifically designated for the purpose, the recommended weekly dose brings Cl up to about 1 ppm. The make I had acquired, Aqua Chem "Shock Plus" seems to imply a most powerful action but is touted "For all pools, including Vinyl, Plaster, and Fiberglass", and allows you to "Swim in as soon as 15 minutes after use". Sounds too good to be true so comments invited from all quarters

 

[anonapersona]

This is one way to do it.

Please do your homework to find out how much CYA that will add.

Check the Pool Calculator at the bottom where it says Effects of Adding Chemicals and use Dichlor at whatever concentration that is.

You will want to, at the top of the Calculator, find out what your FC range will be. Assuming that you test and when you find that the pool is at the low end of the recommended range, then add chlorine to get to the high end of that range. Then you need to know your pool to see how often you will be doing that. Most folks report a drop of 2 ppm per day, some experiance more than that, up to 3 or 4ppm. So, just to run the numbers, assume that you lose 3 ppm per day, as a start, or 21 ppm a week. You would be doing this on a daily or alternate day basis with small doses, but easier at this point to look at the weekly effects for the rise in CYA.

So, if you are adding X oz of dichlor at y% per week find out how much your CYA goes up with that addition. Then put that new CYA number into the Pool Calculator and refigure your dosages as they will go up as your CYA starts to climb.

I found that in my pool it would create a rise in CYA of 19 per week, based on needing to add 21 ppm of chlorine per week. You'd need to drain water pretty soon at that rate of rise in CYA.

 

[dmanb2b]

it is too good to be true, because it is simply di-chlor or another form of stabilized chlorine which will eventually overstabilize your pool.

Also a level of 1ppm will almost guarantee you an algae bloom. As the previous poster said...you need to read pool school a few times over and be willing to follow the principles outlined there and you pool can too be a Trouble Free Pool.

 

[anonapersona]

I think we need to define a Trouble Free Pool....

Test your pool chlorine (and maybe pH) each evening or even every other evening.

When it gets to the minimum chlorine, add a jug of bleach (while pool is running and has an hour to circulate still)

If you must, adjust pH as necessary to keep in range for comfortable swimming.

If you toy with the Calculator and determine how fast your pool consumes chlorine, you can fine tune this to something like a little jug or a big jug on some regular schedule like every day or other day or third day. It may take adjusting the CYA to find that sweet spot. But you still test, to know if something is up and if the schedule is suddenly not regular.

Brush weekly, test the other stuff weekly or monthly depending on your pool. Check the skimmer and pump basket daily or on whatever schedule your pool demands. Clean the filter when you must.

 

[dalehileman]

"Also a level of 1ppm will almost guarantee you an algae bloom."

My most abject apologies for my massive ignorance but my Cl-Ph indicator from friendly local Pool Store labels 1 ppm as barely adequate, with levels up to 3 ppm as "ideal"

"When it gets to the minimum chlorine, add a jug of bleach (while pool is running......."

Thanks most kindly for the suggestion but if it's this easy I can't help wondering why the Pool Establishment even continues to sell trichlor

Incidentally terms like FC and CYA leave me cold, feeling I must surely have selected the wrong site, where my college chemistry doesn't do much good but where one needs to be a PhD so can someone at least provide a link to Pool Abbreviations--thanks once again

PS: I had thought CYA means "Cover Your Fannie." But what on earth does "overstabilize" mean? It's like a warning against "excessive happiness"

 

[anonapersona]

My most abject apologies for my massive ignorance but my Cl-Ph indicator from friendly local Pool Store labels 1 ppm as barely adequate, with levels up to 3 ppm as "ideal"

And what CYA level do they label as "ideal"? My strips say CYA 30-50 is "Ideal". Going to the Chlorine - CYA chart I see that at CYA 30 that 3 ppm is in fact the ideal chlorine level (assuming you have no Combined Chlorine and are measuring only Free Chlorine), right between min and target FC and at CYA 40 you would still be OK for the most part. At CYA of 50 that 3 ppm really is not enough unless you are depending on algaecides or other chemical$.

What the strips don't do is to tell you what happens when you get away from that Ideal level.

"When it gets to the minimum chlorine, add a jug of bleach (while pool is running......."

Thanks most kindly for the suggestion but if it's this easy I can't help wondering why the Pool Establishment even continues to sell trichlor

:lol: :lol: The short answer is because people are too lazy to test their pool every day. Everyone wants a magic potion that lets them not have to do anything but jump in the pool when they wish. Or, that seems to be what many of the professionals see in their customers.

Read some of the posts here about pool store stories and you may figure out that what is good for the pool store is not necessarily what is good for the pool.

Incidentally terms like FC and CYA leave me cold, feeling I must surely have selected the wrong site, where my college chemistry doesn't do much good but where one needs to be a PhD so can someone at least provide a link to Pool Abbreviations--thanks once again

http://www.poolcalculator.com/chemistry.html#FC s if you need someone to show you around the site.

You really ought to spend a little time exploring the site on your own. Instead of going straight to the Deep End, which is where the experts talk about the finer details, you need to spend that time in the regular areas learning the ins and outs of this way of pool-keeping.

If you are open-minded and willing to do some work yourself and not be spoon-fed all your information then you will probably enjoy this site. Start with Pool School. Play with the Pool Calculator, the upper part as well as the lower sections.

It is not hard to learn, most of it is about maintaining chlorine with respect to the CYA level. There are 5 choices for chlorine source, each has some issue. Two add CYA, one adds calcium, one does not store well over time and needs to be tended nearly every day, the last one is expensive to install and introduces some additional chemistry effects.

Beyond that, there is a little bit of chemistry with TA and pH, but if your pH is holding OK you can skip that.

 

[Ohm_Boy]

I can't help wondering why the Pool Establishment even continues to sell trichlor

I may be able to help you with your query. Chemical companies love trichlor.

The pucks have a long shelf life, they are easily stored and transported. They marketed as a simple "toss in and forget it" solution for the pool owner.

Allow me to spin a made-up tale about no one in particular... [ahem]

Once upon a time, someone buys a new swimming pool. This is a major investment, so our owner vows to be meticulous in following the pool store's advice. The pool owner buys a huge tub of trichlor tabs from the store, along with a tab floater and a couple of cartloads of other chemicals, and it works well for the first season. The owner and the store become fast friends as the owner buys stabilizer and weekly doses of dichlor shock and ph-up and toys and cleaners and floats and all sorts of stuff for their new pool. Man, this is the best summer ever. Lots of work, though. And funny thing - it seems that every test of the pool water is somehow beyond the normal limits and needs to be adjusted with some product or another. And we really can't understand what we're doing wrong, 'cause we're doing exactly what the store says to do. Season two starts off with a bit of a mess from the winter, but enough cal-hypo clean-up "shock" and some algaecide and some more tabs and we're good again. We probably need a new net this year. Maybe one of those inline chlorine feeders, too. Our owner is getting pretty tired of that floater. And now that the owner is an experienced pool owner, his confidence is up - he's ready to spend some more money and take it to the next level, so maybe he'll get an automatic pool cleaner as well. He'll need it as the season winds down, because he's starting to see algae in his pool. Year three and the algae is bad. Pool store says he needs more shock. Done. Still getting algae. Pool store now tells him that he has "chlorine lock", and needs some algaecide. Still more algae? Hmmm... must be that he's developed a "chlorine resistant" algae - let's check the phosphate level. Oh my - that looks like the problem. Owner now buys some expensive phosphate remover. Thank goodness for that pool store. Who would have known about looking for "algae food" in the water? Whew - the algae looks like it might be gone now, but there are stains on the pool still. More algaecide? Maybe some sequestering agents. Then some clarifier. Maybe some floc. The ph is all over the place, and we can't get the TA in line either.
The dude at the pool store now says that the water may be over-stabilized. Owner will need to drain some water and start over. That'll put the pool back to where it was about halfway through season two. This pool owner will be ready to fill in his pool soon, if he's not already. Meanwhile, the pool store, and consequently the chemical companies, are rolling in it all the way to the bank. So naturally, the market folks think that trichlor is wonderful.

Of course, this is completely hypothetical, and doesn't reflect anyone's actual experience.

:lol: :lol:

 

[Guest]

Incidentally terms like FC and CYA leave me cold, feeling I must surely have selected the wrong site, where my college chemistry doesn't do much good but where one needs to be a PhD so can someone at least provide a link to Pool Abbreviations--thanks once again

Properly taking care of a pool is not hard but you will have a learning curve just like with any new skill IF you will click on the link in the upper right of every page labeled "Pool School" and take a few minutes to read everything there (it won't take long since the vast majority of aritcles are about half a page and the longest ones are less than a full page) it will get you up to speed about proper pool care. There is even a "definitions and abbreviatons" article to handle that problem.
After you have read it, read it all a second time. Then post any questions about what you do not understand. You do not need to be a chemist to take care of a pool but you do have to have a basic understanding of what is going on in your water and what you WANT to go on in your water.
As an analogy, you do not have to study at the Cordon Bleu to be able to cook but you do need to know the difference between a teaspoon and a tablespoon and know the difference between boiling and broiling!

As far as dichlor goes, it will overstabilize a pool faster than trichlor. For evern 10 ppm of FC added by dichlor you will also add 9 ppm of CYA (stabilizer). The average pool loses 1-2 ppm FC daily. If we take the best case of 1 ppm that means you are adding 9 ppm of CYA every 10 day (27 ppm a month) so if you started at 0 ppm CYA you will be overstabilized at the end of 2 months since the normal range for CYA in a manually chlorinated pool is 30-50 ppm. In actual practice most pools lose more than one ppm FC a day.
The only way to remove CYA is to drain out water and replace it with fresh water. Water added to make up for evaporation will not lower CYA.
If you do not know what overstabilization does to a pool then just ask.

BTW, where are you located. Location does matter in the best way to care for a pool as climates differ.
Also, the type of pool you have also matters. If you wouuld click on 'control panel' in the upper left and create a 5 line signature with your pool info in it we can help you better. Also if you put your location in your profile it would also be helpful.

 

[chem geek]

Incidentally terms like FC and CYA leave me cold, feeling I must surely have selected the wrong site, where my college chemistry doesn't do much good but where one needs to be a PhD so can someone at least provide a link to Pool Abbreviations--thanks once again

PS: I had thought CYA means "Cover Your Fannie." But what on earth does "overstabilize" mean? It's like a warning against "excessive happiness"

As was suggested, take a look at the Pool School where you can become familiar with the abbreviations and common terms used. CYA stands for Cyanuric Acid and is also known as "conditioner" or "stabilizer". It is a chemical put into pools to protect chlorine from degradation from sunlight. Without any CYA in the water, about half of the chlorine will break down in noontime sun in around 35 minutes.

The problem with CYA is that it significantly reduces chlorine's effectiveness since most of the chlorine binds to the CYA forming compounds that do not sanitize much (if at all) and do not oxidize bather waste so don't help keep a pool clean. Fortunately, it doesn't take very much active chlorine to kill most pathogens, but algae takes more active chlorine to kill. So if the CYA level gets too high and you don't raise the chlorine level to compensate, then algae can grow faster than chlorine can kill it.

Trichlor and Dichlor products are already chlorine combined with stabilizer (CYA) so when you use such products you are increasing the amount of CYA in the water. For every 10 ppm Free Chlorine (FC) you add with Trichlor, it also increases CYA by 6 ppm. For every 10 ppm FC you add with Dichlor, it also increases CYA by 9 ppm. Even in a pool with a low 1 ppm FC per day chlorine usage, if you use Trichlor as your sole source of chlorine, in just 6 months it will add over 100 ppm CYA to the water if you don't have significant water dilution.

Forget what the pool stores are telling you about "recommended" levels of chlorine (FC) and stabilizer (CYA). It is the ratio of these that is important. This is known science since at least 1974, but is not taught by the industry, courses or pool stores.

Richard

 

[dalehileman]

"The problem with CYA is that it significantly reduces chlorine's effectiveness since most of the chlorine binds to the CYA forming compounds that do not sanitize much (if at all) and do not oxidize bather waste"

Thank you kindly waterbear and geek for those rundowns, it's getting clearer. Can I assume then from what you've explained that CYA buildup isn't reflected by my regular Cl-Ph check and therefore I need a new and completely separate means to measure CYA

Also can I infer from what you and waterbear have said that "overstabilization" (a word I don't find in the Pool School link to abbreviations) is a condition where the CYA is so high that the Cl isn't working in spite of "normal" readings of its concentration

 

[reebok]

Thank you kindly waterbear and geek for those rundowns, it's getting clearer. Can I assume then from what you've explained that CYA buildup isn't reflected by my regular Cl-Ph check and therefore I need a new and completely separate means to measure CYA

correct. knowing your CYA level is a key element of proper testing. either of the two recommended test kits have this test with them, thought the one from www.tftestkits.net is a better value.

Also can I infer from what you and waterbear have said that "overstabilization" (a word I don't find in the Pool School link to abbreviations) is a condition where the CYA is so high that the Cl isn't working in spite of "normal" readings of its concentration

CYA is also known as stabilizer, and usually has that word as opposed to CYA on the container on the store shelf. it may also say conditioner. so yes, overstabilization means too much cya. and "normal" (assuming you mean pool industry standards) amounts of chlorine are only effective to 30ppm CYA max. you would be hard pressed to find any pool that uses tabs that have a cya that low, though you may find SWG pools that have cya that low or lower (which is bad for SWGs but as seen on this board is propogated by some builders and pool stores despite what the SWG manual says). so no matter which way you turn, you're going to find bad or incorrect advice from pool industry sources.

 

[Guest]

"The problem with CYA is that it significantly reduces chlorine's effectiveness since most of the chlorine binds to the CYA forming compounds that do not sanitize much (if at all) and do not oxidize bather waste"

Thank you kindly waterbear and geek for those rundowns, it's getting clearer. Can I assume then from what you've explained that CYA buildup isn't reflected by my regular Cl-Ph check and therefore I need a new and completely separate means to measure CYA
In a word, yes.
There are more than just total chlorine and pH that need to be monitored and adjusted to maintain a pool. Your two way tester only measures total chlorine, which is not that useful except as a quick check of whether there is chlorine in the water or not, it will not tell you if it is free chlorine (able to sanitize) or combined chlorine (chlorine that has already reacted with ammonia and other oganics in the water and is not useful anymore).
The parameters that need to be tested and ajusted are
Free Chlorine
Combined chlorine
pH
Total Alkalinity (the measure of bicarbonates in the water--important for maintaining pH. The carbonc acid/bicrbonate buffer is the main buffer system than helps maintain the pH in pools.
Calcium hardness (most important in both plaster and fiberglass pools but for different reasons, less important in vinyl unless it's too high)
CYA (Where you put your FC depends on where your CYA is. The higher the CYA the higher you need to run your FC to have the same equivalent available chorine in the water.)
There are some other tests that might need to be done in certain circumstances such as salt for pools with salt water chlorine generators or borates if they have been added as a secondary buffer system or for algae control or specific metals if there are problems with staining or metals in the fill water or for ammonia and/or nitrate when there is an extreme unexplained chlorine demand. However, these speciality tests are done on an as needed basis.

Also can I infer from what you and waterbear have said that "overstabilization" (a word I don't find in the Pool School link to abbreviations) is a condition where the CYA is so high that the Cl isn't working in spite of "normal" readings of its concentration

Exactly! If you are using trichlor and/or dichlor the odds are that your pool is overstabilzied or will become overstabilized along with the problems it causes. If you have a cartridge filter it is a certainty that will happen within one or two seasons. If you are adding algaecide on a regular basis, get any kinds of algae in the pool, get cloudy water, or need to shock to get rid of chloramine smells on a regular basis then I will bet the farm your pool is overstabilized.

 

[dalehileman]

"You really ought to spend a little time exploring the site on your own. Instead of going straight to the Deep End, which is where the experts talk about the finer details,....."

No question about me being lazy, wherein I was relieved for example to hear the advantage of trichlor over bleach. The idea of having to mess around with my pool chemistry every day is positively appalling. One has also to eat and sleep, pull weeds, bathe, etc and that is why I so much appreciate the immediate advice from experts here

Again thanks all

 

[dmanb2b]

If you soley use trichlor..you'll want to have your TA on the high side and be prepared to perform routine drain and fills as your CYA level will climb over time

 

[dalehileman]

Thank you dm for that insight, I was glad to learn that some of these values change so very slowly, saving me just that much more free time so that I can better clear the weeds

I maintain my Ph around 7.6 so wondering if you think this high enough

 

[frustratedpoolmom]

"You really ought to spend a little time exploring the site on your own. Instead of going straight to the Deep End, which is where the experts talk about the finer details,....."

Quote Button, upper right corner of the post box. Give it a try.

No question about me being lazy, wherein I was relieved for example to hear the advantage of trichlor over bleach. The idea of having to mess around with my pool chemistry every day is positively appalling. One has also to eat and sleep, pull weeds, bathe, etc and that is why I so much appreciate the immediate advice from experts here

I test/add bleach every 2-3 days. I have a very light bather load and keep the pool covered when not in use, losing less than 1ppm daily with no swimmers.

I tested PH about a week ago, last time I tested was about a month ago, no adjustment needed either time.

I tested TA about a month ago, no adjustment needed.

I tested CYA in May when I raised it up a bit.

I tested CH about a year ago, nothing has been added to the pool which would change it.

I know my pool like the back of my hand, It's hardly an afterthought. Can't get any lazier than me.

 

[dmanb2b]

Thank you dm for that insight, I was glad to learn that some of these values change so very slowly, saving me just that much more free time so that I can better clear the weeds

I maintain my Ph around 7.6 so wondering if you think this high enough

A PH of 7.6 is fine. I was commenting on TA. Low TA (ie 60-70) tends to keep pools that have features which tend to increase PH via aeration.. such as a waterfall feature or SWG from experiencing rapid PH rise.

Conversly, I higher TA...lets say 130-150 will help offset the acidity Trichlor tabs provide, hence preventing rapid PH declines...with time your Trichlor tabs will reduce PH and TA, so you'll likely need to add baking soda every so often to maintain your optimal TA level.

You'll also ask what is my optimal TA level...well it depends, it's a trial and error type of thing. Unfortunately, although you may think Thrichlor is a low maintenance option...it's what predominately brings the 10K plus members to this forum. Eventually it will add so much CYA that your chlorine added via the tabs becomes ineffective. Also covered in Pool School.

 

[dalehileman]

"I test/add bleach every 2-3 days.......PH about a week ago, last time I tested was about a month ago, ......TA about a month ago......CYA in May when I raised it up a bit......CH about a year ago...........
I know my pool like the back of my hand, It's hardly an afterthought. Can't get any lazier than me. "

Oh yes I can. It's becoming apparent that testing--especially exotic values like TA, CYA, etc--is very controversial as I get the impression that daily measurements of all this stuff is almost fanatical

 

[frustratedpoolmom]

Quote button, upper right corner of the post box. Give it a try.

 

[Guest]

"I test/add bleach every 2-3 days.......PH about a week ago, last time I tested was about a month ago, ......TA about a month ago......CYA in May when I raised it up a bit......CH about a year ago...........
I know my pool like the back of my hand, It's hardly an afterthought. Can't get any lazier than me. "

Oh yes I can. It's becoming apparent that testing--especially exotic values like TA, CYA, etc--is very controversial as I get the impression that daily measurements of all this stuff is almost fanatical

They are not exotic values. They are standard water tests that every pool store does when you bring in a sample, that every health department requires for a commercial pool, and that every pool owner SHOULD be testing at home if they want to maintain their pool properly.

http://www.urbandictionary.com/define.p ... alehileman
From the Urban Dictionary:
dalehileman

an irritating, repetitive message board poster.
yo, if you dalehileman one more time, dude, I'm gonna ban you from this forum!

Interesting, no?