Finally drained my pool due to 100+ CYA level

Wes45

0
LifeTime Supporter
Feb 15, 2009
74
Garland, TX
I finally replaced 40-50% of my water yesterday and the test results from this morning look good:
50 CYA
0.5 Cl
7.5 PH
300 CH
70 TA
Water temp 80 degrees - I thought it would have been cooler. I was surprised using the Pool Calculator that my recommended Cl level is between 4-8. I thought it would be in the 2-3 range with my CYA at 50. Does this make sense?

I'm going to add 131 oz of bleach now to get it to 4. I'll be checking the Cl daily to see what it takes to keep it at 4.0, of course with the forecast here in Dallas 99 degrees and sunny through Sunday it will likely take more than usual this week.
All my neighbors that have chlorinators in their pools and are using the 3" tri-chlor tabs like I was think I'm crazy for draining my pool. Has anyone else experienced that? They say "What's CYA, I never test for that."
 
Speaking from personal experience, you are going to be extremely happy with your lower CYA level. The pool will be much easier to maintain at lower chlorine levels.

It's still amazing to me that the relationship between pucks, CYA and chlorine is NEVER mentioned in pool stores. I used my puck feeder for almost 3 seasons, thinking it was the easiest thing in the world... of course, all of season 2 I was battling algae, and season 3 I was told to do a partial drain. I'm very thankful to have found this site!!!

Just from some comments on the site, I think some folks get better mileage from their feeders because they may backwash a lot, or get a lot of rain, splashout, etc.. that might keep CYA slightly more under control. However, I'd be willing to bet they'll all have issues at some point...
 
You are well on your way to a trouble-free pool.

I once had a pool store employee tell me that I didn't need to worry about CYA.

4-8 is correct. So each night, test, and add enough bleach to reach 8. This will keep you above 4 at all times, which is your minimum and will keep you algae free. If you use a solar cover, depending on bather load, you may not have to add bleach for 2 days with that target. My pool loses very little FC when it's covered and not in use, I can go 2 days without having to add bleach. After a while you will get to know your pool's demand and get in to a routine too.

It may seem like your neighbors aren't having trouble but pools have one thing in common. You can't walk away and let them take care of themselves, that's just asking for trouble. And you aren't watching their pool 24/7 I guarantee they will have problems from time to time and who knows how much they are spending on unneccesary chems to correct potential problems.

BBB is a piece of cake, you'll have no regrets. :goodjob:
 
Just chiming in to say you will never regret ditching the CYA. Pool water management will come much easier for you from now on.

Yeah, I've had people look at me like I had two heads (I looked in the mirror.....I don't :shock: ) when I tell them I put just Clorox in my pool. I learned a long time ago not to worry about the funny stares in the checkout line.

YOur Daily FC loss should average around 2ppm of FC....give or take. I would suggest bringing FC up to 6ppm each evening and testing the following evening to see how much you lost. If your pool is like most, you'll be down around 4ppm and you'll never have to shock all summer. You also may not need to backwash/clean more than once or so.

Very nice work! :-D
 
Thanks for all the feedback. I checked it last night and had a small, light patch (approx 8 inch square) of green algae on the side of the pool and my Cl was around 0.5 again. I dumped in a 182 oz bottle of bleach and got the Cl to 6 and checked it again this morning and it was still at 6. Will check again tonight and think if the Cl is down to 0.5 again and there is any algae that I need to shock the pool? It's been close to 100 degrees and sunny yesterday and today so not sure if that is taking all the chlorine out. Any ideas?
 
If your FC holds overnight you are usually good to go, but the fact that you saw visible algae and had that much of a drop - you should bring it up to shock level tonight, and then perform the overnight FC loss test.
 
What's next?

Superchlorinated the pool last night using 3.2 jugs of 182 oz bleach to get Cl=16. Ran the pump overnight and all day today, sunny and hot in Dallas, around 95 degrees. Just tested using the FAS-DPD method and CL=6.5. Did I kill the algae? Do I do the overnight test to insure it doesn't change overnight from the 6.5? Do I superchlorinate it back to 16 since it dropped almost 9.5 points in 24 hrs? I just can't seem to get this rectified.
Your input is appreciated.
 

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Doesn't it matter that my Cl dropped 9.5 points from 7PM yesterday (Cl=16) to 7PM tonight (Cl =6.5)? I was expecting it to only drop 2-3 points so I thought I still had a problem even though my water is sparkly, my CC=0 and I didn't see any algae anywhere in my pool. I misread the "done shocking" part because I thought I had to shock it again so I just dumped in 2 jugs of bleach to get it back to Cl=16. I guess I didn't have to do that?

So regardless of how much the CL drops from tonight until 7PM tomorrow, I should do the overnight test tomorrow and if the CL drops less than 0.5 and since my water is sparkly and CC=0, I am algae free should follow the program and keep my Cl between 4-8?

I wasn't expecting to be so confused/frustrated. Thanks for your help, hopefully I am very close to getting things right.
 
Can you go out and test tonight? Then compare tonight's test result to a test you take first thing tomorrow morning.

When FC levels are high, you lose a % of FC, not a set number. The average daily FC loss in pools is 2-3 ppm, but when your FC is elevated, you will lose more, often 50% or so.

To do the overnight test, you test after dark, 30 minutes after the last bleach addition, then again first thing in the morning, and compare. Waiting until tomorrow evening won't tell you anything.

If you can't test tonight, then wait until tomorrow night to perform the overnight test. However, be sure to keep your FC at the recommended levels in the meantime.

Does this make sense?
 
Thanks, that makes sense. I'll just have to wait until tonight to do the overnight test. I didn't realize that losing 50% or more of the superchlorination levels was normal, I guess I need to spend more time in Pool School. :hammer:

If the worse thing it cost me was 2 jugs of bleach and another day of not swimming in the 99 degree heat in TX, that's OK.
 
We just did our first shock using the BBB method and following the instructions from Pool School and the overnight test. It took about 2-1/2 days of keeping the FC at the shock level (Sat evening to Tuesday am). We brushed a couple of times, vacuumed once and backwashed once. I'd say we used about (8-9) 174 oz bottles of bleach when it was all said and done. (BTW, Family Dollar Brand - $2.50/174 oz.) Finally, on the third morning, our FC only dropped 1 ppm and we called it Good Enough! Yes, I was about out of POP, but we hung in there and hopefully it will be smooth sailing from here on out.
 
Thanks for the post Lolly, good to hear there is light at the end of the tunnel. What did your water look like and did you have any visible algae?

Then there is Sallie on another topic who has been at it for 10 days!
 
Our water was perfectly clear but had light patches of algae on the walls and in the seams of the liner. It just wouldn't hold FC at all before we found this site. Sunday was the first full day we shocked and each time we tested, the FC had dropped considerably. We couldn't be home all day but had we been, it probably would have been better to check it hourly or so rather than every few hours as we had to. That way it wouldn't have dropped so much between testing. Instead the FC dropped below shock level a few times and we had to add lots of bleach.

Monday went better, it didn't drop nearly as much so we were able to keep it at or above the shock level all day. By Tues am it was perfect.

I was about to give up but it was worth sticking with it!
 
No if it says 6% then that's what it should be. Sometimes though we have had reports of users who dose with the bleach and never reach the level they were targeting for - that's usually a sign that the bleach is old and has lost it's strength...and is no longer 6%. Your's may have been fine, I'm just saying more often than not we have bad reviews of dollar store and also Big Lots bleach.

Store generics from Walmart, Target, etc. and Aldi have all been fine. Your's worked for you so all is good! :goodjob:
 

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