Brand new to TFPC, need advice on handling high CYA level and chemistry for closing

[ekalbs4]

I came across the site looking for answers on what to do about my high level of CYA and how to prepare my pool chemistry for closing. I wish that I had not waited until pool closing time to learn about the TFPC methods!

I just started noticing that the stabilizer number at the bottom of my test strip seems to be way up in the dark pink/purple high range somewhere between 150-300 ppm. Before now I had pretty much ignored this test because it had always seemed just fine and I had never learned about the pitfalls of CYA. I’m not sure when it actually started being out of range. I had no idea there was any concern about CYA levels. I’ve done lots of reading about CYA on this site for the last two days.

Knowing what TFP has taught me, I’ve shut off my chlorinator and removed all of the chlorine tablets. By doing this I also learned that the screen at the bottom of the chlorinator was very clogged, which would at least partially explain why I’ve been having a hard time the last few weeks keeping my chlorine level up. I had been resorting to using granular shock more often, which now I know was making my CYA even worse. I ordered the TF-100 test kit today. In the meantime I took a water sample to the pool store and got these test results:

FC = 0
CC = 0
PH = 7.0
TA = 110
CH = 210
CYA = 225

Pool store recommended that I add 2 gallons of 12.5% liquid chlorine (which I’ve now done) and use another gallon each weekend until I’m ready to close my pool, at which time I should come back in for another water sample to be advised again before closing. I had been going to this pool store every few weeks all year, but learned that they never wrote down my CYA level in their test records. No wonder I was oblivious to this issue. I guess you get what you pay for when it’s “free” sample testing. Also, several hours before adding the liquid chlorine, I also decided to brush my pool and add some algaecide and clarifier, thinking that will lower my chance of having an algae problem get started. Water looks clear and no signs of a problem. In fact, over the last two years I've never had an algae problem and have pretty much always had clear water.

This will be my first time closing my pool and now I’m confused on what my order of operations and timing of events should be to deal with my CYA issue and also to properly close my pool within the next few weeks. I’m hearing that before closing I need to shock, or I guess SLAM now, but it seems like that will not be practical to do at my high CYA levels. I was planning to lower the water below my skimmer anyway, but the Pool Math is showing I need to lower around 80%. Pool store said I should lower down to about 1 foot of water and refill. The other trick is that in order to discharge my water to the sewer drain (my only viable location for this much water) I need the chlorine level to be zero per my city regulations. Lastly, the pool store is saying (in general to all customers) not to close until the water temperature is 50 deg. F if using a mesh style safety cover (that’s me) or 60 deg. F if using a solid cover (not me). I'm likely going to need to wait 3 weeks for my temperature to drop, so during that time do I continue using liquid chlorine?

I'm having trouble figuring out which way to go with all of these variables. I would really appreciate some TFP advice.

 

[domct203]

Welcome to the forum.

I would recommend you stay in a 'holding pattern' until you get your own test results. The CYA test is the one that most pool stores get wrong.

In a 15K gallon pool, two gallons of 12.5% would have added 17ppm of FC. Without knowing an accurate CYA level it's hard to advise if that is adequate or not. If your CYA is really 200ppm, your minimum FC level is 15ppm & should never fall below that or you risk algae & bacteria/virus blooms.

If algae should develop you would need to raise and maintain a FC level of 80ppm, an unrealistic goal, and why we consider that CYA level as unmanageable. The only reliable way to lower CYA is to drain a portion of the pool & refill.

While you wait for your test kit, add 3/4 to 1 gallon of 12.5% chlorine (or about 2 large jugs of 8.25% plain laundry bleach) daily. When your test kit arrives we can get an accurate set of results and plan our options.

Also, 7.0 is a bit on the low side for your pH. Do you have any water features you could run to aerate the water? Aeration will naturally raise pH.

We generally recommend that water temps are below 60F when closing, the lower the better. Normally cover type doesn't influence this, but the colder the better if your cover will let in UV.

 

[kimkats]

While you wait for your test kit, add 3/4 to 1 gallon of 12.5% chlorine (or about 2 large jugs of 8.25% plain laundry bleach) daily. When your test kit arrives we can get an accurate set of results and plan our options.

The above post is purrfect! (THANKS Dom!) I just wanted to point out an important word in it--------daily as in adding the chlorine daily. I noted your Pool $tore said to add it weekly.

You are on the right track. Let us know when you test kit gets there. We have some tips on doing a couple of the tests (CYA being the big one).

I am SO glad you found us! Your Wallet will be glad also!

Kim

 

[ekalbs4]

Thank you domct203. I'm pretty stressed out about this and reading your initial response was like hearing, "everything will be okay, we'll figure this out". Thanks for that.

It looks like my test kit is not scheduled to arrive until next Monday.

I hear what you are saying about the pool store getting the CYA test wrong, but in case it's relevant to know, on that same day I took two water samples to two different pool stores. At the second store he indicated that their CYA tester only went to 100 and that my reading must be well above that.

Since my test kit is not coming until Monday, I had been thinking about using this weekend to go ahead and do a partial drain since two pool store tests and the test strip are all showing high levels. Even if I don't know the exact magnitude, it seems like some level of drain and refill is likely. For now, I picked up 8-64 oz. 8.5% Clorox bleach at Ace Hardware for $1.99 ea. regularly $3.49 ea. It's on sale through the end of the month. Good timing! If I'm going to do a drain, I'll need time to allow the chlorine level to come down to zero. Not sure how long that will take.

Regarding pH and aeration, no I don't have any water features and no I'm not going to go splash around in 64°F water!

Good thing (I think) is that there is an unusual two day cold spell (at least the daily low temp) coming. High today was 63°F and low tonight is 38°F. High tomorrow is 62° and low is 29°. Those daily low temps are unusual, not typically until after Halloween for freezing. I'll keep my pump running all night. After those two days the daily lows go back to about 50°F. My water temp. right now is about 64°F. I've been leaving my solar cover off all day to try and get the pool temp down. These next two nights should help.

- - - Updated - - -

I just wanted to point out an important word in it--------daily as in adding the chlorine daily.

Thanks kimkats for emphasizing daily.

 

[kimkats]

You can go ahead and do some draining. The worst that can happen is your drain too much and will have to buy some CYA if you get it too low. No big deal. It is MUCH easier to add than to take out.

Have you seen Pool Math yet? Look up at the top of this page. It is one of the pretty blue ovals. There is a learning curve with it. Start playing with to learn how it works. Down at the bottom make sure to change the setting to Trouble Free Pool levels.

Kim

 

[Kiss4aFrog]

Welcome to TFP ekalbs4

Please don't wait to stop using the Rainbow inline feeder. If there are tablets in there now I'd go pull them. It's just adding more CYA right now as I type.

 

[ekalbs4]

You can go ahead and do some draining. The worst that can happen is your drain too much and will have to buy some CYA if you get it too low. No big deal. It is MUCH easier to add than to take out.

Have you seen Pool Math yet? Look up at the top of this page. It is one of the pretty blue ovals. There is a learning curve with it. Start playing with to learn how it works. Down at the bottom make sure to change the setting to Trouble Free Pool levels.

I probably will drain to be efficient with my time this weekend. I have started looking at Pool Math. What does the jug size drop down in the top right corner do? I'm not seeing any difference when selecting.

- - - Updated - - -

Please don't wait to stop using the Rainbow inline feeder. If there are tablets in there now I'd go pull them. It's just adding more CYA right now as I type.

Got it. I actually mentioned in my initial post that I did that. Thanks for double checking!

 

[Kiss4aFrog]

Sorry. Poor reading skills. I saw it in your signature that you were planning to remove them.

 

[ekalbs4]

I did move forward with partially draining my pool this past Sunday in anticipation of having a high CYA reading, even before receiving my TF-100. I connected a hose to my filter's air vent and drained into my garage sink. With this method, I avoided having to worry about getting my FC to zero in order to discharge to the storm drain per city regulations. I estimate that I drained about 30%. I don't really want to lower too much more than I did because I'm thinking it's probably best to keep some water above my lowest step (vinyl over wedding cake steps), or at least no lower than the top of the bottom step. I started refilling Sunday and completed on Monday. Then on Monday night I added 4 - 8.25% 64 oz. containers of bleach.

Now on Tuesday night, here are my first TF-100 test results:

Results from poollogger.com

FC: 12.5
CC: 0
PH: 7.5
TA: 120
CH: 150
CYA: 120
Temp: 58

First time that I did the chlorine test I got FC of 15 and 0.5 for CC, but then after reading the tips about not going too slow, I repeated and got the 12.5 and 0 readings. The PH reading was tough to judge. For the CYA, I did let the water sample sit for about 1 hour indoors. I stood over the CYA test tube that was standing on the dining room table under the bright dining room light.

My pool temperature has been consistently below 60°F for the last week and I would like to close this weekend, but looks like my CYA is still very high. For closing, I'm planning to drain to below my returns, which should help a little, but probably not enough.

 

[tim5055]

Welcome to TFP!!

How did you get the CYA of 120? Did you conduct a diluted test ot get this number?

Anytime your FC is above 10 the pH reading is going to be artificially high, but with a 7.5 I wouldn't worry about it now.

I'm not sure what your water cost it, but all lowering CYA at this point is doing is allowing you to use a little less liquid chlorine for the next three weeks until you close (unless there is algae I missed in a post somewhere).

If it were me and the water was clear/no algae I would just keep the FC correct for the next three weeks and close. With your mesh cover and rain/snow over the winter you should end up with a good reduction in the CYA over the winter.

 

[domct203]

I did move forward with partially draining my pool this past Sunday in anticipation of having a high CYA reading, even before receiving my TF-100. I connected a hose to my filter's air vent and drained into my garage sink. With this method, I avoided having to worry about getting my FC to zero in order to discharge to the storm drain per city regulations. I estimate that I drained about 30%. I don't really want to lower too much more than I did because I'm thinking it's probably best to keep some water above my lowest step (vinyl over wedding cake steps), or at least no lower than the top of the bottom step. I started refilling Sunday and completed on Monday. Then on Monday night I added 4 - 8.25% 64 oz. containers of bleach.

Now on Tuesday night, here are my first TF-100 test results:

Results from poollogger.com

FC: 12.5
CC: 0
PH: 7.5
TA: 120
CH: 150
CYA: 120
Temp: 58

First time that I did the chlorine test I got FC of 15 and 0.5 for CC, but then after reading the tips about not going too slow, I repeated and got the 12.5 and 0 readings. The PH reading was tough to judge. For the CYA, I did let the water sample sit for about 1 hour indoors. I stood over the CYA test tube that was standing on the dining room table under the bright dining room light.

My pool temperature has been consistently below 60°F for the last week and I would like to close this weekend, but looks like my CYA is still very high. For closing, I'm planning to drain to below my returns, which should help a little, but probably not enough.

Sounds like you got the hang of the FC test, that's great.

The CYA test should be done outdoors on a bright sunny day, with your back to the sun. Hold the view tube with two fingers at the very top, and don't let your hands block any indirect light. While holding the view tube at about waist level add the sample until you can not see the black dot when glancing at it. You want to let in as much indirect light as possible, but keep the tube in your shadow to eliminate glaring reflections.

I like to add the sample until the dot starts to get hard to see, then I look at the numbers and fill to the next level, check the dot again & if I can still see it, I fill to the next level and repeat until I can no longer see the dot with a glancing view. There are no "half-way" readings (45, 65, etc), always round up to the next number (eg half-way between 40 & 50 is considered 50).

Indoor lighting is going to give you false results.

Also, if you are getting a CYA of 90ppm or above, you should do the Extended CYA Test to get a more accurate reading as 90-100ppm is really the limit of the test.

From the link above:
"If your CYA level is 90 or higher, repeat the test adjusting the procedure as follows:

• Fill the mixing bottle to the lower mark with pool water.
• Continue filling the mixing bottle to the upper mark with tap water.
• Shake briefly to mix.
• Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark.
• Continue the test normally from step 3, but multiply the final result by two."

Once you have an accurate CYA you can use the FC / CYA Chart to manage FC levels, then follow the Closing and Winterizing your Above Ground Pool procedure to put the pool to bed for the winter.

All your other levels look fine for closing. Your TA is a bit high, but we can deal with that in the spring.

 

[kimkats]

For PH I hold a white, plastic plate up behind the tube at should level and pull the plate back and forth until I see the color match.

Kim

 

[ekalbs4]

Welcome to TFP!!

How did you get the CYA of 120? Did you conduct a diluted test ot get this number?

Anytime your FC is above 10 the pH reading is going to be artificially high, but with a 7.5 I wouldn't worry about it now.

I'm not sure what your water cost it, but all lowering CYA at this point is doing is allowing you to use a little less liquid chlorine for the next three weeks until you close (unless there is algae I missed in a post somewhere).

If it were me and the water was clear/no algae I would just keep the FC correct for the next three weeks and close. With your mesh cover and rain/snow over the winter you should end up with a good reduction in the CYA over the winter.

I did use the diluted test procedure to get the 120. I do not have, nor have I ever had, any algae problems, so I'm leaning towards closing without doing a SLAM, which would require using a ton of chlorine.

- - - Updated - - -

The CYA test should be done outdoors on a bright sunny day, with your back to the sun. Hold the view tube with two fingers at the very top, and don't let your hands block any indirect light. While holding the view tube at about waist level add the sample until you can not see the black dot when glancing at it. You want to let in as much indirect light as possible, but keep the tube in your shadow to eliminate glaring reflections.

Indoor lighting is going to give you false results.

Also, if you are getting a CYA of 90ppm or above, you should do the Extended CYA Test to get a more accurate reading as 90-100ppm is really the limit of the test.

I used indoor lighting that was shining directly down into the tube, so that probably made it easier for me to see the black dot then if it were indirect outdoor sunlight, which would mean my CYA is even higher. I'll try the test again if I can catch some sunlight. I did use the extended CYA test. Thanks for the additional testing advice.

- - - Updated - - -

For PH I hold a white, plastic plate up behind the tube at should level and pull the plate back and forth until I see the color match.

Good idea, thanks!

 

[ekalbs4]

Is it a waste of time and money to add "a bunch" of liquid chlorine before closing, even if I know the resulting FC level (per Pool Math) is not going to reach the required level for my CYA level to properly shock? Is there still some benefit or is it somehow detrimental? I have 6 - 64 oz 8.25% bottles of bleach that I plan to add. I estimate that I would need closer to 13 bottles just to get to shock level (assuming target FC around 50).

 

[MarianParoo]

How soon are you closing? Another trip to the store for more chlorine could save you come spring.....

 

[ekalbs4]

I was wanting to close my pool this weekend. I'm off work today, so was planning to brush and shock today and close on Sunday.

I did a Chlorine drop test last night at 8:00 pm and FC was 10. Checked again this morning at 7:00 am and FC was 9. If I wasn't closing, it would seem that a shock is not necessary, but should I add to shock levels anyway because I'm closing?

I've now repeated my CYA test. My first test was with indoor lighting. It is overcast today, but hopefully testing with outdoor lighting is more accurate, even when there is no blue sky.

Here are my latest test results for today,

Results from poollogger.com

FC: 9
CC: .5
PH: 7.4
TA: 110
CH: 175
CYA: 140
Temp: 58

My PH reading is still just a guess. It was somewhere between the 7.2 and 7.5 markers I suppose. Can't believe the test kit does not offer something easier like the drop methods. The CYA test outdoors was difficult because I kept seeing a reflection (my head probably) that was hard to ignore. Finally figured out it wasn't the dot I was seeing.

 

[ekalbs4]

The Chlorine/CYA Chart page has a link to a post of an older table that includes this info:

NOTE: A reasonable approximation to the above table is the following:
.... "Min FC" is 7.5% of the CYA level
.... "Target FC" is 11.5% of the CYA level
.... "Yel/Mstrd Min" is 15% of the CYA level
.... "Shock FC" is 40% of the CYA level
.... "Yel/MstrdShock" is 60% of the CYA level.

This is very valuable info for those of us with a CYA level higher than 100, which the other table does not address. I don't see any TFP folks making reference to this info, even when the person asking for help has a CYA over 100. Is this information still valid?

 

[kimkats]

This info is very valid! It is where the chart came from. We try to keep things simple and easy to use. We found a chart with ranges works best for most people (myself included).

It is best to get/keep the CYA at the recommended levels for many reasons. The main reason is the effort and cost of keeping the FC at the correct level to keep your pool clean.

Kim

 

[ekalbs4]

I closed my pool this past Sunday. I got these test results before closing:

Results from poollogger.com

FC: 17
CC: .5
PH: 7.6
TA: 110
CH: 150
CYA: 140
Temp: 57

For closing I lowered my water below the returns, so between that and winter rain/snow hopefully my CYA level will be reduced in the spring. Thank you so much to TFP for helping me out. I have to say, after doing the TF-100 tests for the very first time, I was thinking "what have I got myself into", but after only a few more rounds of doing the tests it became easy and fun. I'm looking forward to putting this into practice for a full season.

Thanks everyone!