Is CYA Absolutely Necessary???

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dunginhawk

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Jul 10, 2018
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I know there are some older threads, and Ive read them... There are valid points made on both sides..

The reason I ask is this. I have had my pool for 2 weeks. Because of heavy rains (and pumping out water a lot because of it) and the cover is not yet on (auto cover) I have decided to wait until the cover is on to balance chemicals fully.
This is resulting in roughly the following numbers (posted on another thread as well, thats what got me thinking)
PH - 7.9-8
FC - 2 ish
CC - 0 (ive tested FC and CC because im trying to figure out my SWG numbers).
CYA - 0
Hardness - 100-120
TA - 70-80

So 2 weeks of nearly daily use without any balancing (just letting the SWG run at 60% w/ pump 24/7 which it always will be anyway). and I have zero issues.
My eyes have never been able to be open under water before, day after day.. Now they can be. The water is crystal clear. Clothes is not fading out. Skin isnt itchy. I cant see a single issue with where my numbers are.

Now that said, I will likely bring my PH more in line with the 7.6 number.. thats a given.
I Will also likely raise the Hardness to 200-250 just to prevent white buildup (fg pool) on the pool walls.
Other than that, Why should or would I need to add CYA.

Right now I have zero doubt that by the end of the day with sun shining the FC reserves of 2-4ppm built up over night (thats about what it is producing) is gone. Obviously by UV, and bacteria from swimmers etc...
But do I care? Should I care? Can a pool not live for a few hours without any FC?
Remember this is without a cover on...

Once the cover goes on there will be a lot more time during the day even when sunny (its dark color) where FC is being produced, not eaten. So the need seems even less so after I get the cover on..

Please dont take this post the wrong way, I am still learning... You have all been super helpful from Nov til now with my hot tub balancing, and im very thankful for the help.
I am a new pool owner, but so far with literally zero work my pool is pristine... Maybe there is some unwanted harm set to befall me, but maybe not??
Like I said, I am still learning, but is a CYA less outdoor pool possible?
Thank you for all the info from the past, and im sure the info to come on this post :) be gentle
 
Possible yes. Practical no. CYA was introduced to pools in the late 50s. Some outdoor commercial pools are still run without it. However it takes continous flow of chlorine into the pool to keep it up due to breakdown by light. It's not practical. I saw some recent information that public pools with little to no CYA could take 8.5ppm of FC each day to maintain. That's a lot of chlorine.
 
Well, with my pump running 24/7 I am giving it a constant flow of chlorine, right? Not trying to be a smarta$$, sincerely...
As I mentioned above, I would fully expect most of the chlorine to be gone on a bright day where the cover was open. However at night it could easily get back up to 2-4ppm...
I appreciate the feedback. I welcome the dialogue.
 
I'll let others chime in.

Looks like your SWG would wear out quickly and you'd risk having inadequate FC levels without adequate sanitation. You might also have increased acid demand because of this and have to install an acid injection system to keep up with it. To prevent water born illness, you always want a sanitizer in your pool. Others??
 
IMO you're putting unnecessary stress on your SWCG, and you'll use it up quicker with no CYA in the water.

If you were using chlorine you'd see the cost immediately. Your SWCG is hiding the cost. At least until it dies on a Friday night before your next pool party.

I'd rather use CYA and less chlorine.
 
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You’re also using a lot of electricity running your pump 24/7, which you wouldn’t needed to do with some CYA.
 
A pool can live for a few hours without FC. Except that is the time algae can take hold in the water. Slowly the algae, which is invisible, will consume more of your FC and eventually overwhelm the SWG CL output. So things will look good until they don’t.

Adding CYA and running the proper FC level will let you keep your pool pristine.

Having a cover and being in IA gives you much less of a FC demand then a pool in the South.
 
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I have no problem opening my eyes underwater, my swim clothes do not fade, my skin is never itchy and my water is gin clear.
My CYA is 30, my FC ranges from 6.5 to 3.5 and my pH is a rock steady 7.8.
My daily FC loss is 2ppm. Pool maintenance is a snap.

Try your system without CYA and keep us posted on your specifics.
 
if you don't mine paying the money for electric by all means keep doing what you're doing. It works don't fix it. CYA kind of puts the chlorine to sleep so its not as active. it protects the chlorine from the sun so its not as potent either. This is why commercial pools shy away from CYA(bather load). That is how it was explained to me.
 
I figure for $14 per season, CYA is a pretty good deal versus running the SWCG 24/7/365....I suggest you'd better take it apart once a month and check for scaling too. 25% solution of 31 Muriatic acid for 15-20 seconds cleans the metal plates nicely. But the end cap so you can fill it. I have Pentair IC-40. By the way....one of my "ideas": I was thinking about seeing if I can install a solar collector/converter nearby pool equipment to power ONLY the pump / heater / SWCG and pool lights....and THEN run it 24/7. I have not yet done the calculations.
 

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There are valid points made on both sides..
Click to expand...
I see no valid points for not using CYA.

It is pretty obvious to thousands upon thousands of pool owners that CYA is an essential part of the TFP methodology we teach.

Anyone can manage their pool water chemistry as they think best, but not using CYA is not a practice we teach.
 
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Let's put aside the fact that you are making assumptions about how adding CYA will affect the feel (incorrect assumptions), and that your pool will stay clear even as the summer heats up (pretty unlikely). I guess we can also put aside the fact that a pool with zero FC is not safe to swim in. I will even set aside the statement that you made about there being valid reasons not to use CYA in an outdoor pool but failed to share any of them, perhaps knowing that we will pick them apart with glee.

Ok, all those completely valid and important reasons aside, let's just go to one simple thing: You are running your SWG 5-10x more than it needs to be and using CYA will extend the life of your SWG 5-10x. Getting that much more life out of a $600 item seems like a no-brainer to me.
 
Let me be clear... I am not saying I wont use CYA. I use it in my hot tub... Im fine using it... I plan to use it.
I am simply a person who likes to know why, how, etc... I want to learn about the alternatives (not those crazy mineral things).
I absolutely trust what you guys (who have owned pools for 1,000,000 cumulative days more than me) say.

So my pump will run 24/7 anyway, which means my SWG will also run 24 hours a day... Now I may be able to ramp it down to 20% when the cover goes on which will put considerably less load on the SWG.
Power is cheap here.. I can run that pump for 15$ a month... It will run May - Sept. thats our swim season.
Most things I read/watch say if you can afford to run your pump 24/7 do it. Granted there will be more wear.

As far as the SWG (and this is a serious question). Would it be harder on the SWG to run at 60% for 8 hours a day? or 20% for 24? Thats something I dont know. I would think more time at a lower level, but again, you guys are more seasoned than me.

So the statement was made that CYA extends the life of your SWG... Is that simply because you wont need to run your SWG as often? or as hard? Perfectly valid answer if true, however as I mentioned I will likely be running 24/7. However since Im a new Pool owner I may fiddle around with things and set a schedule on the pump for 8 hours a day during the evening or something instead of 24/7 just to see how things react. However during that 8 hour window as I mentioned I would likely have to ramp up the SWG to a higher percentage (60-80) to get the same FC over a shorter window.

Again, please please please understand I am not disagreeing with anyones comments. This is a learning thing for me. Everyone has had their own positive (and some negative) experiences that have led them to this point in their pool care. If at the end of the day I subscribe whole hog to all things TFP it will have been because I learned from you all and lessons taught me it was the best method.
 
There are some great older threads on the site by Richard Faulk aka Chemgeek - he was the one who helped spearhead all of the current TFP numbers and was I think responsible for the super useful FC/CYA Chart.

Here is an article mentioning the history of this information and a great quote from the article:

"at 4 ppm of free chlorine with 30 ppm of CYA at a pH of 7.5 that swimmers are exposed only to 0.112 free chlorine (4.0 ppm × 0.028 = 0.112 ppm). In contrast, at even 1.0 ppm free chlorine without CYA results in an exposure of 1 ppm of free chlorine. So having CYA in the water results in an exposure to chlorine 10 times less than without it. "

Basically - if you have zero CYA, then even a FC of 1 is much much stronger chemically than say CYA 30 and FC 4.

I think probably our best current and actively posting chemistry expert is @JoyfulNoise (aka Matt) - I am sure he can explain this better than I could, and with actual scientific numbers...
 
Your SWG has a fixed amount of CL generating capacity determined by the coating on the plates. It makes no difference if you run it 10% for 10 hours or 100% for 1 hour. You bought a given amount of CL with the cell. Use it as much as your pool needs.

The wastage comes from not protecting the CL from the suns UV. Rather then the CL you generate accumulating in the water to provide sanitation the UV eats it up.

Being in IA CL loss to UV is a lot less than in TX or AZ due to a lower sun angle.

Every pool has a unique environment it lives in. You have to learn what works for your pool. A pool is a dynamic chemical body that interacts with its environment.
 
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Hi, I have also just started my pool that has a SWG too. I am also running my pump 24/7, however not at full speed, I have a variable speed pump too. I assume you are also not running on full speed? Then running 24/7 does not have to cost extra electricity.
With CYA, your SWG does not need to work as hard as without CYA. So, the cell will last longer. The reason is that less Chlorine is used with a higher CYA and the proper FC value for that CYA.
Running the SWG on 60% for 8 hours is the same as running it at 20% for 24 hours. If you run a SWG at less than 100%, it will just turn on and off frequently. When running at 60% it may run for 6 minutes and then turn off for 4 minutes.
Another advantage of CYA is that when chlorine is used at a spot in your pool, the CYA immediately will release new chlorine at that spot, so that the FC level is restored quickly in case of a contamination.
I am using trichor tablets in a floater to build up CYA, together with the SWG. So, the SWG does not have to work very hard.
 
dunginhawk said:
As far as the SWG (and this is a serious question). Would it be harder on the SWG to run at 60% for 8 hours a day? or 20% for 24? Thats something I dont know.

So the statement was made that CYA extends the life of your SWG... Is that simply because you wont need to run your SWG as often? or as hard?
Click to expand...

You are asking some AWESOME questions!! Ones I have not thought about but very worthy of asking. I am going to read and learn with you!

Kim:kim:
 

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