# Thread: Helping BIL out, want to make sure I am correct

1. ## Helping BIL out, want to make sure I am correct

My brother in law has had his house with pool for a year now. Was using tablets to balance it. Calls me up last week in a panic because it's now green. I bring my trusty TF100 tester over and his CYA was something ridiculous like 120-130. Couldn't tell exactly because the test vial didn't go that high. I have him convinced to use the BBB method I learned on here.

Today the pH was 7.8 and the FC was 9. We add some muriatic acid and bring the pH down to 7.5. So now we are ready to shock it. Am I correct in my math that he will need close to 1,800 ounces of bleach to reach a shock level? I found the CYA to FC level chart on here and the highest CYA listed was 100. The shock level for that is 39. If he is at the CYA level of 120, would 45 be an accuarate guess for shocking? I just want to make sure I am steering him the right direction. His pool is a plaster in ground, about 24,000 gallons.

Thanks for the help.

2. ## Re: Helping BIL out, want to make sure I am correct

To get a better check on the CYA level use half pool water and half tap water. Then do the test and when the dot disappears take that reading X 2.
Your going to have to drain and replace some water to get the CYA level down for the SLAM process. Current level is wayyyy to high. If you could get it down to 50 that would be great. Use Pool Math to figure out how much water needs to be replaced. 😎

3. ## Re: Helping BIL out, want to make sure I am correct

Anything 100 and over could be as much as 350 ppm or even more. Need to do at least a 2 to 1 tap to pool water test. Multiply the 2 to one results by 3. If that doesn't give you a readable number (lower than 90) do a 3 to 1.

4. ## Re: Helping BIL out, want to make sure I am correct

If cya is really that high he would be better off if y'all could replace the water rather than slam at that high lever and continue to maintain CL at that high of CYA. If that is possible where you are.

5. ## Re: Helping BIL out, want to make sure I am correct

Redo the CYA test using the dilution method in Extended Test Kit Directions.

If you scroll down to the bottom of poolmath and select TFP, bleach, and the correct pool surface in Suggested Goal Levels, then plug in whatever CYA number you arrived at, it will tell you shock level in the box labelled Suggested FC Levels.

You do realize after the SLAM, that the minimum FC level is going to be higher than any test kit without the FAS-DPD tester can read, right? If BIL doesn't have his own test kit, it'll go green again.

6. ## Re: Helping BIL out, want to make sure I am correct

Ok thanks everyone. This is exactly what I needed to know. I wasn't crazy about having a FC level that high. I will redo the CYA and see what we end up with. He has access to a water truck so maybe it's the better way to go. Will have to pay for the drivers time but I believe the water is free.

I wasn't aware the pool math tells you how much water to drain. What a great resource. I love this site!

7. ## Re: Helping BIL out, want to make sure I am correct

Keep us posted on how things go. 😎

8. ## Re: Helping BIL out, want to make sure I am correct

BTW, before I came over to help him he took a sample to the pool shop and he said that his CYA was 150. ��. I'm telling him he needs to drain the pool and he really doesn't want to do it.

9. ## Re: Helping BIL out, want to make sure I am correct

Well if doesn't replace some water, he's going to have problems all the time. Plain and simple ! 😎

10. ## Re: Helping BIL out, want to make sure I am correct

Well......that comes up on this forum. You can't make him.

You can lead a horse to water but you can't make him drink. If your BIL is in doubt, all you can do is give him the information. He will have to decide to want to learn and trust his own testing and your advice or to keep doing what he has been doing.

11. ## Re: Helping BIL out, want to make sure I am correct

Show him YOUR pool and tell him how YOU do it! Seeing is believing for many.

He is off to a better start than so many others in that you have a test kit to show him. Maybe buy him a test kit as a gift? Throw in a bottle/jug of chlorine LOL

Kim

12. ## Re: Helping BIL out, want to make sure I am correct

Thanks everyone. I couldn't agree with you all more. Thanks to this site I have a clear understanding of not only how to keep my pool clear, but how every part contributes to an enjoyable, healthy experience. I will continue to work on him.

BTW, if the pool shops CYA is correct, he's looking at replacing 67% or 16,080 gallons of water to bring his CYA down to 50. Those Costco tablets are not so convenient now.

13. ## Re: Helping BIL out, want to make sure I am correct

That's a BIG if. Do the dilution test I recommended. That's the only way you'll get a good estimate of what his cya might be. I wouldn't ever trust a pool store's cya results.

14. ## Re: Helping BIL out, want to make sure I am correct

So he took another sample to the pool shop. CYA was 150. I would like to test it myself doing the method described above but I just have to get access to his pool. The guy at the shop wants him to add more Low n Slo and then flock. I flocked a couple times at the pool shops recommendation before I found this site and had mixed results. Clumped up the algae pretty quickly, but I still had a cloudy pool after I vacuumed. I know it's not the way to go and I try and tell him that, but he wants to try this before draining the pool.

It's exactly what was said above, you can lead a horse to water but you can't make him drain his pool. From my basic understanding of what I have learned on this site, if this does clean it up he needs to keep a sharp eye on the pH or he is going to have the same problem again very quickly. Is that about right? I really want to him to drain the pool to get his CYA down and then use the method on here but I can't force him.

So if I understand what all is going on correctly, if this clears his pool up what do I tell him he needs to watch out for? Keep the pH in line, and run a higher FC to match the CYA? If I can get him to start using liquid chlorine vs the tablet, will his CYA eventually start to fall, or is draining the pool the only option?

15. ## Re: Helping BIL out, want to make sure I am correct

Will fall maybe only minimally. Replacing water is generally the best option. Sometimes you just gotta bite-- not take-- the bullet.

16. ## Helping BIL out, want to make sure I am correct

I wouldn't even know what FC range to shoot for with a CYA of "150". If that is any where's close to being accurate. I have my doubts. 😎

17. ## Re: Helping BIL out, want to make sure I am correct

Originally Posted by odonekanobe
So if I understand what all is going on correctly, if this clears his pool up what do I tell him he needs to watch out for? Keep the pH in line, and run a higher FC to match the CYA? If I can get him to start using liquid chlorine vs the tablet, will his CYA eventually start to fall, or is draining the pool the only option?
Essentially, if you keep pH in range and maintain the proper FC/CYA ratio, the pool will be fine 90% of the time. Maybe even more than that. The pool can be maintained with that super high CYA. I've done it, so I know. But it was not easy, nor do I recommend it to anyone, and I certainly don't recommend it to someone who isn't completely onboard with our methods.

CYA does not break down any noticeable amount over the swim season. It only gets removed by backwashing, splashout, or draining.

18. ## Re: Helping BIL out, want to make sure I am correct

Originally Posted by Richard320
Essentially, if you keep pH in range and maintain the proper FC/CYA ratio, the pool will be fine 90% of the time. Maybe even more than that. The pool can be maintained with that super high CYA. I've done it, so I know. But it was not easy, nor do I recommend it to anyone, and I certainly don't recommend it to someone who isn't completely onboard with our methods.

CYA does not break down any noticeable amount over the swim season. It only gets removed by backwashing, splashout, or draining.
I was thinking that might be the case. I will gently mention it to him although I think if his pool clears up he won't really consider it. Not much I can do at that point.

Thank you everyone for your help.

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