1. ## CYA overshot!

I have a 24' x 52" Intex Ultraframe (yes, I know this needs to go in the sig....)

Finally got the pool up and filled. Tested Daily and started adjusting towards balance. CYA was zero and added Conditioner, now CYA is approximately 120! The PoolMath calculator says to lower CYA, I need to pull water and replace.

FC 0.5 ppm - added 1g 10% Sodium Hypochlorite
CC 0.5ppm
PH 7.0
TA 175
CH 200
CYA 120
Salt 3800 (SWG replacement arrives Tuesday)

Do I need to drain/replace? How much and how fast? Any other options?

2. ## Re: CYA overshot!

How much conditioner did you add?

3. ## Re: CYA overshot!

I added 6 pounds of this Clorox stabilizer from Lowes. I was at 0 and the directions say 4 pounds for 30ppm, so I went more instead of easing into it.

4. ## Re: CYA overshot!

6lbs of stabilizer in 13,500 gallons of water only raises it 53ppm. Pool School - PoolMath

I'll take a guess the 120 came from a test strip or a pool store "free" test.

5. ## Re: CYA overshot!

No, I am using the T100 test kit. I also bought the salt test kit.

Any tips on how long to wait before starting a replacement routine? I understand I will not get to stability on the salt system that arrives today until I get the CYA down. So besides adding chlorine daily, do I need to watch for something else?

6. ## Re: CYA overshot!

Hmelton, you are in an awkward position really. Sure, you could start to replace water starting at about 50% to see how that works for you. But like Pooldv noted above, if our pool size (gallons) estimate is correct, 6 lbs of stabilizer should only get you to a CYA of 53 according to the calculator. 120 is a huge disparity. You have a great test kit, so before you drain, let's confirm a few things:
- Are we sure the gallon size we are using for your pool (13,500) is correct?
- Are you absolutely sure on the amount you added?
- Is there any chance you may have made a mistake on the test itself?

I don't mean to insult you or your information, but I'd hate to see you drain so much water only to find-out there was something else at fault. But if everything above seems spot-on, your only option to lower CYA is to do a healthy drain. I mentioned 50% drain, but definitely don't go any lower than 1 foot to the bottom though for your pool to avoid messing-up the liner or frame set-up. As for when to drain ... well, if you added the CYA about a week ago, which is how long it takes to fully register, then you can start now. Keep us posted.

7. ## Re: CYA overshot!

Did you do a dilution test to figure out 120? How many gallons is your pool?

8. ## Re: CYA overshot!

Are you using dichlor or trichlor pucks, shock or powdered chlorine? Those all raise CYA.

9. ## Re: CYA overshot!

Defgufman: The size is 13,500 gallons and I used the TF100 test kit.

pooldv: no pucks but I am using liquid shock from Leslies, it does not list CYA but there are 90% 'other ingredients'. I guess I need to pick up chlorine tonight.

IF I am TRULY at 120ppm CYA, then do I need to run FC closer to 10ppm until I get it resolved? While it will be a pain, do a partial drain would let me fix a frame post issue (I'm high on one side, the sand compressed differently around the pool, should have used paver sand which locks together better).

10. ## Re: CYA overshot!

Typically here, if someone says they are 100+ in CYA, we recommend a good healthy drain to lower. While you say it "may" be 120, there's really no way for us to know for sure because the CYA test only goes to 100. We've seen people who thought they had 110 and were actually closer to 200. So if you do confirm the high CYA of 100+, then your best bet is to drain before adding any more chemicals. Trying to keep enough bleach in a pool with a CYA of even 100 would be a Target of 12 and SLAM FC of 39! That could get exhausting.

11. ## Re: CYA overshot!

If you dilute pool water with equal amount of tap water and get a reading of 60, then I agree with your 120 estimate and would target 14 FC and not let it get below 8 until you can do your partial drain/refill.

12. ## Re: CYA overshot!

Daniel, that is the info I needed. I had not thought of simulating a dilution scenario. Perfect.

13. ## Re: CYA overshot!

Used a 50/50 test and CYA 140, FC 6.5 this morning. Off to pick up bleach and then install the SWG tonight.

14. ## Re: CYA overshot!

Hmelton, if your CYA is 140 based on the dilution test, you really would be best advised to drain/replace some water. Since your water is new, and you simply overdosed the conditioner during initial fill, you do have that option to try and maintain the high FC level that will correlate with that high CYA, but that's risky. If in the future your water turns cloudy/green and you need to SLAM, you will go through a LOT of bleach. That may be a trade-off you are okay with for now, just wanted to be sure you knew. Your call neighbor.

15. ## Re: CYA overshot!

I am planning on the drain fill this weekend. Just need to get there safely first. Work first unfortunately.

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