CYA to high

[badwater]

I found out by reading on this site that CYA being to high can cause algae growth. I'd never heard of cya before this. My pool is cloudy green for the third time in the last two months, I've been "pool stored" beyond belief and need help. I just bought a test kit at Walmart that will do a cya test and my level was 100. I understand a drain and refill is the only way to correct this, but how much do I need to drain? 50%?

Thanks!

 

[scott.MI]

You should try an extended test, you may very well be over 100.

mix 50% pool water with 50% tap water, mix it and use that as your "pool water sample" and double the results, then report back. I think the CYA test is supposed to be done outside during the daytime sunlight hours.

If your pool is still green you will need either a test kit with FAS-DPD chlorine test, or you can buy just the FAS-DPD chlorine test as a stand alone.

Just to clarify, most cya tests max out at 100, so anything at or above 100 will read as 100. If you do the extended test and get a result of 50, you are truly at 100 (50x2=100), but if you get 70 with the extended test, that means your around 140 (70x2=140). It is actually pretty common to be over 100 especially from pool maintenance methods.

 

[timerguy]

I've got to ask, who makes the test kit and what model is it? I've never seen a test kit at Walmart that did cya.

 

[scott.MI]

HTH makes a 6 way test kit that does test for CYA. http://www.walmart.com/ip/HTH-6-Way-Test-Kit/17043668

Just doesn't have the FAS-dpd test.

 

[badwater]

What Scott.MI said...

 

[duraleigh]

I'd never heard of cya before this.

You are not alone. Your first step should be read "The ABC's of Pool Water Chemistry" up in Pool School. That'll tell you about CYA, it's function and how it relates to the other essential answers you must test for.

Knowing how to do dilution testing, or going to get an FAS/DPD test does not help you if you have no idea what anyone is talking about, yet..

 

[Richard320]

You're on the right track now. That test kit will suffice if you add the FAS-DPD test to it. I'd get one ordered up soon, and hopefully you'll get it before the pool turns thick enough to walk on.

CYA by itself doesn't cause algae. But high levels of ot can render whatever chlorine is in the water ineffective. It's essentially sunscreen for the chlorine. A little sunscreen lets you tan while preventing crippling sunburn. High CYA is like smearing so much SPF 100 on you that you look like a ghost. My first season I successfully managed to keep my pool clear despite CYA levels over 200. But that required FC levels above 20, and there's only one tester that can read that high. Sadly, now that your pool is cloudy, you will have an extremely difficult, expensive time clearing it without draining some CYA.

How much? That depends on where you are. You know where you want to go, but you don't know exactly where you're at. As mentioned above, try the dilution method and see if you can get a better reading than 100+ At this point it's like getting map directions only knowing what city you're in, when you need to know what street you're on.

While you await the test kit, study up some in Pool School.
http://www.troublefreepool.com/content/123-abc-of-pool-water-chemistry The basics.
http://www.troublefreepool.com/content/139-recommended-pool-chemicals What to add and how to add it
http://www.troublefreepool.com/content/114-poolmath-pool-calculator How much to add
http://www.troublefreepool.com/content/125-slam-shock-level-and-maintain-shockingl What you'll be doing eventually.

People have cleared far worse than a little cloudiness using these methods. Here's some inspiration. I like the pictures more than all the discussion, myself.
http://www.troublefreepool.com/threads/79787-Gone-for-2-months-and-return-to-a-swamp
http://www.troublefreepool.com/threads/74959-How-much-chlorine-will-I-need-(gross-numbers)
http://www.troublefreepool.com/threads/75213-the-pool-is-winning
http://www.troublefreepool.com/thre...-the-TFP-Forum!!!-Another-Green-to-Clean-tale
http://www.troublefreepool.com/threads/76128-TFP-Success

It all seems like too much, but once you start doing, it will make sense. By August you can have clear sparkling water that will invite comments and be the envy of all who see it.

 

[timerguy]

What Scott.MI said...

Great, hope it has directions for a diluted test like Scott suggests. If it doesn't, do it how Scott suggests. Hope you get an accurate result to use in your calculations. Good luck with it!

 

[badwater]

Ok, I just did the diluted test and got a number of 52ish, so it seems like a real number of 104 is pretty close. I just ordered a taylor k2006, it should be here Monday. In the meantime, can I begin to drain and refill? Or am I jumping the gun and should wait for the test kit and get more results? I would like to take advantage of the weekend to get this started if possible. Thanks for everyone's help, this is an awesome resource!

 

[duraleigh]

It's a direct reduction. drain and refill 50% of your pool and your pool's CYA will drop by 50%.

 

[timerguy]

You want to do that to leave a foot in the pool to keep it from collapsing so 52% of your water needs to be replaced to get you to 50. What is the depth of your pool? 4.5 ' maybe? so drain and refill approx 2 1/3 feet.

 

[badwater]

Pool is 54" deep, so drain 27" and refill? Just so I am clear with what I am doing, am I SLAMing once the pool is full?

 

[timerguy]

That should do it, or get close anyhow.

 

[badwater]

So, am I slamming when the pool is full?

 

[Richard320]

So, am I slamming when the pool is full?

Yes. Because you need to have the pump running. After you've drained, it wouldn't hurt to pour some bleach into the stream of water from the hose and brush it around. But don't expect that to do anything but keep things from getting worse.

 

[Casey]

While you're pool is draining and filling, you need to be reading the ABC's of Pool Water Chemistry. This article is going to give you the know how, once your pool is full. Do not skip this... As Duraleigh pointed out, you will learn about CYA in the article since you have no prior knowledge of what it does and how it acts.

Once you complete the ABC's of Pool Water Chemistry, it would be beneficial to you to also read:

Recommended Pool Chemicals
How to Chlorinate Your Pool
Chlorine CYA Chart

You will then be ready to under go SLAMing Your Pool with complete confidence because you pt the time in to read these very short articles in Pool School. Yes you'll have questions but not as many. Ask away when you do. We'll be here to guide you through it.

 

[badwater]

Just finished with the 50% drain and refill. I dont have my k2006 yet but here are the numbers from the HTH:
C-(OTO) 4
ph-7.3
TA-110
CH- 160, sample only turned yellow
CYA-60
Heres a question I'm not sure I want the answer to: should I drain more to get the CYA down even more? I drain about 20-25% for winter so am hoping this will be ok until next years refill.
Thinking I need 60oz baking soda to sneak up on the TA a bit. Since I dont have my "good" test kit yet, any recommendations on how much chlorine (clorox 8.25%) I can add to get to shock level, based on the oto reading? Thanks for all the great info, SUCH a great site!

 

[Richard320]

Leave the TA alone. More draining is your call. If the pool is green and opaque, draining may help. If it's just tinted a little, get going with the bleach. 4.5 jugs of Clorox will get you up to shock level of 24 for 60 CYA. What you'll do after that is sort of up in the air without the tester.

 

[badwater]

Sorry to take so long to update the progress. It took five days of slamming for the water to clear, all numbers are great and pool is sparkling clear! Thanks to everyone for the great advice, the pool store will never see me again!

 

[tim5055]

Great job!!

I will just caution you on the nature 2 you have in your signature. If you are still using it you are adding metals to your water that you probably don't want.