High CYA and High Clorine

Jurate1

Well-known member
Apr 22, 2021
78
Tucson
Pool Size
8000
Surface
Plaster
Chlorine
Liquid Chlorine
Hello all I have a few questions. My pool guy let my CYA levels get to high. I have recently let him go and am trying to manage on my own,
Here are my current numbers. I have a few questions. I had water test done at pool store and also compared to strips. I have tried using the pool test kits recommended but I have a difficult time differentiating the colors in the test tubes. The pool looks good. Water is clear, no algae. Apx 8000 gallons.

Free chlorine 9.74
Total chlorine 9.74
PH 8.2
Alk 119
CYA 146
Phos 22

I have added PH down to bring down PH

I have been holding off partially draining pool to see if CYA levels would come down via evaporation but very little movement. I live in Arizona and it is now over 100 most days. Pebble tech pool. Is it safe to partially drain maybe 1/4 of pool? Can water drop below skimmer outlet? I am afraid to damage pool. I can hook up the hose to the overflow valve on the pump and run down sewer.. How long do I drain? Since pool has the auto refill will it refill itself or do I need to put hose in the pool?

Finally I have read multiple posts that recommended that FC should be 7.5% of CYA levels. So I added more liquid chlorine. Levels as above. Pool store states it is not safe to swim in and may damage equipment. But other sites say the chlorine is bound to the CYA and so it is ok to swim...

Thanks for your input. Gina
 
Pool stores don't understand the chemistry. The chlorine is bound to CYA and that buffers it.

CYA does not leave the pool when water evaporates. The only ways are splash out, a leak, overflow, or intentional draining. You have to remove liquid pool water with the CYA in it to get it out of the pool.

What you posted are obviously pool store numbers the recommended test kits don't have you trying to guess colors, except for the pH test. Taylor K-2006 or TF-100 are what you need.
 
Thank you. I do have the Taylor test kit as well as strips. Will try again. Could you assist with the pool draining. Is it really just simple. Attach hose and let it drain for 30-60 minutes into sewer? Any precautions?? I don't want to damage our sewer or the pool...
 
Prior to draining, please post a full set of test results from your own test kit.

In Tucson, you have little concern of ground water floating the pool shell. With your volume, the easiest thing is to rent a high power sump pump from Home Depot with enough hose to get to your sewer cleanout. In the late afternoon, drain the pool down (should only take 3 hours or less) and then start the refill right away.

Once done, circulate the pool really well, including a good brushing, and retest the pool water chemistry. Post the results here and we can guide you on the path forward.
 
My test kit does not do CYA. Here are other results. I have the k1004
Cl =5
Br=10
TC=5
Alk 50 not sure I did this right. It turned pink after 4 drops but red after 5 drops
 
Without test results from a proper test kit, TFPC cannot provide guidance on water chemistry. So decisions based on your testing are your own.
Do a complete drain. If you believe the test data you are basing it on.
With your volume, the easiest thing is to rent a high power sump pump from Home Depot with enough hose to get to your sewer cleanout. In the late afternoon, drain the pool down (should only take 3 hours or less) and then start the refill right away.
 
I realize this is not the specific test kit the forum now recommend but it is a Taylor kit. I bought this months ago before coming across this site. Are you saying all my test results done with this kit are worthless and I should throw away? or just get a separate CYA kit..
 
You do not have bromine. Your chlorine is off the chart high, so a reading of 5 from that kit is not very helpful. All we really know is you have at least 5 ppm of chlorine, but not how much.

You'll need to get the FAS-DPD kit, a pH test, and the CYA test, at a minimum. I happened to price out those things today, to see if picking them up separately is a better deal than the whole kit or not. The kit is less expensive than those three components.

A single garden hose off the pump bib isn't going to cut it. The hose will restrict flow too much, and the process will take too long, risking plaster damage. It also risks burning out your pool pump if the pump were to suck air in from the low water levels. A sump pump really is the safe way to go.
 

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You can buy individual test kits. Do a comparison against what is recommended here and fill in the gaps (CFA, FC, Calcium, etc.). Having an accurate test kit is the most expensive thing you should have to buy and will keep you from making costly and time consuming mistakes. Here is the link to the individual test kits:

 
Thank you all for feedback. I did order a separate CYA test before I saw your response. I will wait and see CYA results before doing any draining. Will order a new test kit in near future. Thanks again everyone.
 
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One additional clarification on the partial drain and refill when I decide to proceed. I know MK recommended draining in late afternoon. However it is still above 90 here in Arizona and also I can't stay up all night watching the hose/refill.. Could I get up early when temp is below 80 say 5:30. Partially drain for 2 hours. Then start refilling at about 8 am. It will still be partially empty during the heat of the day. Not sure best approach. Thanks
 
You really do need to do a full drain in order to get your CYA down to manageable levels. At LEAST 2/3, if we trust your pool store results. If you drain a bit too much, it's easy to add CYA in. If you drain too little, you have to do the whole draining process over again, throwing away some of the newly-added water along with the pool water.

Use a 5 gallon bucket and time how long it takes for your hose to fill it. 18,000 divided by the number of seconds is the number of gallons per hour you are getting. (5 gallons per X seconds times (60 seconds per minute) times (60 minutes per hour) equals gallons per hour) Hose length very much makes a difference in flow rate, so make sure you set it up for the bucket test the same way you will set it up for filling the pool.

Calculate how many gallons you need to refill. If you know the drain pump flow rate, and how long you run it, you can get in the ballpark. Actual flow may be a bit less than rated, due to resistance from the discharge hose.

Then you can figure out how many hours minimum you need to run the hose to refill, so you can sleep soundly. With an 8,000 gallon pool, depending on a number of factors including water pressure and hose length, you can expect a complete refill in (very, very roughly) 11 hours. That's why MK suggested draining late afternoon and refilling overnight, so your plaster doesn't dry out. If you start your refill at 8 AM, your plaster will be baking all day in the sun before the pool fills.
 
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Hello everyone, I just received my test kit in the mail. Here are my numbers. My pool overall looks good. Water is clear.

Free chlorine 7.5
Calcium 300
Alk 170
CL =5
Br = 10
PH 8.2
CYN = 90

So I believe I am above FC required.. (90 x7.5%) =6..75. given CYA 90. . (CYA via test kit much lower then pool store at 134.) With temps over 100 I get quite a bit of evaporation weekly. I think by the end of the summer levels will be more acceptable. It appears to be dropping 5-10 points/month. I believe the only thing I need to do is add more Muriatic acid to bring down the PH... and maintain FC at about 7 is that correct?

I am a little confused on the color changes for test kit. So when it says in the instructions the sample should turn red, it's not really red it's more pinkish hue. Do you stop at the first drop that something starts to turn pink or blue. Or does entire sample need to be a solid blue or solid red/pink?

Finally I know you all do not recommend the Leslie Perfect Weekly but I have a jug of it in the pantry and don't feel like driving to toxic waste dump way on the other side of town... If I use it every week until it's gone will I have any problems? Thanks for your help. Gina
 
Different pools seem to like different PH. Mine likes 7.6 to 7.8 , hangs there quite awhile. Anywhere between 7.2 to below 8 you should be good. Take a bit to find your own sweet spot.
Don’t know what perfect weekly is, so can’t help there. Got lucky and found TFP before being pool stored! 😀
 
Thanks Msch99, , Could anyone comment on my other numbers? Am I on the right track? The PH on my tap water is at the high end PH 7.8. Given that fact should I try to keep the pool at the lower end of PH range so I don't have to constantly add Muriatic acid?

What does everyone do when they go on vacation for 2-3 weeks. My house sitter does not feel comfortable adding chemicals.
I know a puck will raise my CYA which is already high but I don't know how else to maintain Chlorine for several weeks at a time. Suggestions? Thanks, Gina
 
Thanks Msch99, , Could anyone comment on my other numbers? Am I on the right track? The PH on my tap water is at the high end PH 7.8. Given that fact should I try to keep the pool at the lower end of PH range so I don't have to constantly add Muriatic acid?

What does everyone do when they go on vacation for 2-3 weeks. My house sitter does not feel comfortable adding chemicals.
I know a puck will raise my CYA which is already high but I don't know how else to maintain Chlorine for several weeks at a time. Suggestions? Thanks, Gina
You will need to test and add chlorine liquid daily unless you plan on using a swcg
 
What does everyone do when they go on vacation for 2-3 weeks. My house sitter does not feel comfortable adding chemicals.
I know a puck will raise my CYA which is already high but I don't know how else to maintain Chlorine for several weeks at a time. Suggestions? Thanks, Gina

Ideally you can find someone that is willing / able to add bleach to the water while you are out. Do you have a cover for the pool? that would cut down on chlorine consumption.

If you are only going to be away for a week or less, you can sometimes get a way with raising your chlorine to slam levels right before you leave. obviously how long you can be away will depend on your average chlorine consumption and how long it takes your pool to drift down to minimum FC levels

Generally use of pucks is highly discouraged around here. however, in the specific case of being out of town for a 2-3 weeks without anyone available that is willing/able to add bleach to to the pool; the pucks might be your best remaining option.
They will increase your CYA over time, and you will need to be mindful of that. Their effectiveness of the chlorine in the pucks might get lowered by a higher amount of CYA already in the water, but it might slow or prevent a big green pool when you return.

Forward looking, if you will be out often, you might consider SWG, investing in a good pool cover, finding friends that are willing to add bleach to the water... or some combination of those things.
 
Thank you for your feedback. No pool cover. If my CYA are still high at end of summer I will drain pool when temps are lower here in Arizona to eliminate the need for excessive chlorine. Right now temps are headed to 110 in the next few days.
 

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