CYA too high?

cue

0
Apr 18, 2015
11
Weatherford/Oklahoma
I am new to testing my own water. Twice I've tested my CYA using the CYA view tube until the black dot disappears. Both times it never reaches the 100 mark, meaning it is well over 100 ppm? It is an above ground pool with a vinyl liner. I would really rather not change out 75% of my water, and getting the water level too low and I would have to worry about my liner. If I did my math right it would cost about $85 on my water bill for about 10,000 gallons. My pool volume is about 16,400. I dont think there is a R/O service in my area. I'll have my local pool store test it and see what level they say it is. Anything I am missing?
 
Trust your testing. If you have read around here much you have probably seen that not much credence is given to pool store testing. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing.

100 is the limit of the CYA test, so you have to do a diluted test. While the full instructions are in the Pool School, here is the short version. Mix 50% pool water with 50% tap water. Use this mixed sample as your test water. If still at a 100 you will need to dilute more. Here is a great chart by JamesW to explain dilution rates and what you multiply the results by to get an approximation of your CYA level.

Pool water......Tap or distilled water.........Multiply result by

....1...................1................................2
....1...................2................................3
....1...................4................................5
 
You can do a 1:1 tests for you water. One part pool water, one part tap water. Do the test that way. Double your results and you will have your CYA level.

How have you been treating your water? Pucks or bleach?

I understand about not wanting to mess up your liner BUT I am here to tell you that high CYA can mess up your liner and equipment so..............

What you can do is drain and fill several times so that you do not lower you water too much at any one time.

Kim
 
Welcome to TFP cue!

Follow tim5055's advice on testing the CYA. The CYA test is the test which pool stores are the worst at. Using the dilution method above will give you the closest reading that the test can do. The test is exponential so the reading could be much much higher than 100.

With high CYA the best option is almost always to replace the water. RO services are a lot more expensive than replacing water.

There is a new product that just got released to the public to reduce CYA, but if the CYA level is too high to start with that product will be a lot more than to just replace the water.
 
Ok, did some more testing. Just to make sure I did this right. I took 5ml pool water and 10 ml of tap water (at room temp), this got me to the bottom of the label on the red cap bottle. I then filled to the top of the label with the reagent. Shook for 30 sec. I then added the solution to the CYA view tube and got to just a hair under 100. So my CYA is 300 ppm? I have been using chlorine tabs for the last 4 years. If I change my water out and get my CYA in line and if I continue to use the tabs I have on hand which will likely take this entire season. Will I be in the same boat as I am now, with the high CYA?
 
If I change my water out and get my CYA in line and if I continue to use the tabs I have on hand which will likely take this entire season. Will I be in the same boat as I am now, with the high CYA?
You can go to Pool Math and plug in your numbers and down at the bottom you can see what the effect of common chemicals will have on your pool.

It would help us help you if you would add the following information to your signature


  • The size of your pool in gallons
  • If your pool is an AG (above ground) or IG (in ground)
  • If it's IG, tell us if it's vinyl, plaster/pebble, or fiberglass
  • The type of filter you have (sand, DE, cartridge) and, if you know, the brand and model of the filter.
  • If you know, please tell us the brand and model of the pump, and mention if is it a two speed or variable speed pump.
  • Date of pool build/install, particularly important if less then a year old.
  • What kind/model of water test kit you are using
  • Other significant accessories or options, such as a spa , SWG, or cleaner
 
Yes you will. The pucks and any "shock" you have added in the past 4 years adds CYA.

CYA=balance or stabilizer. If you look on the labels you will see they will say something about it.

On TFP we use chlorine/bleach to keep out pools clean and clear.

Some of us use pucks for long weekends and vacations. We make sure we know how high out CYA is and keep track of how the pucks will affect our levels and go from there.

Kim
 
how far can I lower the water level at one time without messing up my liner?
As a guideline, we suggest to always leave a foot or thereabouts of water in the shallow end.

I think it makes the most sense to drain 1/3, then another third, then another if necessary.....refilling and testing after each drain.

I know it's painful now but you have to bite the bullet and ABSOLUTELY get off the pucks as your primary source of chlorination.
 

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Ok. I replaced about 75% of my water and refilled. I am now at about 110 CYA from 300. Using the pool calculator it says I need to drain another 60%. How much will the CYA drop on its own?
CYA naturally drops a few (yea, that slow) points a month. The biggest way to drop cya is to pump water out of the pool whenever you get rain. I started with 200+ CYA and over the course of a year now have it to 60. I did make an adapter to harvest water from one of my roof gutter downspouts. A good rain would raise my level a few inches, then I would circulate it for a while and pump it back down to normal level.

Evaporation will not reduce CYA.

There are a few threads going now relating to a bioactive CYA reducer. So far the results are mixed, but you can take a look at them.
 
I drained about 50% of the water and refilled last night. Re-checked CYA and I am now at 65-70 PPM. A couple of questions about testing method. Do you add the solution to the view tube and as soon as you can no longer see the black dot, that is your reading? Or can you add some solution let it settle a few seconds, look away and continue adding solution until you absolutely can no longer see the dot? If I take the intial reading it is at 100. If I let it settle a few seconds etc.. Its at 65-70.

Prolly splitting hairs, which I tend to do, over thinking things. So assuming my level is in the 65-70 range. What should I do from here? Leave it and let it come down on its own? We will be getting quite a bit of rain for the next few weeks, and its not typically warm enough to swim until closer to June.

Or drain more?
 
You can let it settle to allow any air bubbles to dissipate. Also you can pour it back and forth to get a few reading to see if it is always the same.

I would say that 65-70ppm is manageable ... especially if you are going to get a lot of rain dilution. You just need to maintain the adequate FC level from here on out. See: FC/CYA Chart

What does the water look like?
 

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