My pool seems to want HUGE amounts of chlorine

May 30, 2010
5
I have come to regard my pool as an enemy with whom I am at war. And the pool is winning.

It seems like no matter how much chlorine I put in, nothing works. I've been doing this every spring for several years now. It's time to start looking for new answers.

Details:

My pool is 16x32 rectangular, in-ground, from 3 feet to 5 feet depth. Around 15,000 gallons I think.

It has a vinyl liner.

I'm in Champaign, Illinois. This weekend it's sunny and in the upper 80s.

Our house is somewhat "out in the country". We don't have city water, but our well water is actually pretty good. The well is around 330 feet deep, going straight down into the Mahomet aquifer.

The pool has an automatic cover on it, so it is covered most of the time.

It's a sand filter.

I have a Polaris 280 with a booster pump.

The pool was opened for the season about 3 weeks ago. I have thrown in about 25 pounds of dichlor before yesterday.

Yesterday morning, I began to work on getting the pool ready for the holiday weekend. I put in a bunch more dichlor, probably 5 pounds. No effect at all.

Starting to get frustrated, I began searching the internet and found this site. I decided to adopt the bleach religion. I convinced myself that after years of tossing in huge amounts of dichlor, my CYA must be sky high. So I ran out and bought 12 bottles of 6% bleach, 96oz each. The pool calculator seemed to think I should put in 5 of them, so I put in 6.

No effect. Still no free chlorine.

To get rid of the CYA, I started draining water and replacing it. I've probably replaced around 2,400 gallons of water.

I read something about doing chlorine after dark. So I waited until late evening and threw in 8 pounds of lithium shock, after reading that it wouldn't increase the CYA.

No effect. Still no free chlorine.

So today I went out to find a way to test for Cyanuric acid, to confirm the diagnosis. I got some cheapie little test strips that told me it was normal. I didn't believe that, so I took a water sample to a pool store:

Test results:

Total Alkalinity: 379
Free Chlorine: 0
pH: 7.4
CYA: 100
Total hardness: 298

I've also done a couple of test strips of different brands, with similar results. I'll be ordering one of the better test kits recommended here on this site, but I don't have it yet.

I expected to see a CYA number which would see a record here on tfp.com. If the number had said 500, everything would make sense. But I apparently do not have a CYA problem, at least not right now.

Anyway, the guy at the pool store couldn't tell me why my pool seems so resistant to chlorine, but he said, "I've seen this before. Sometimes it just takes a huge amount of chlorine to get a pool going in the spring. You just need to chlorine the living daylights out of it."

So I came home and assaulted my pool with everything I had left. Since the CYA didn't seem to be a problem, I tossed in about 18 pounds of dichlor. And I poured in 16 bottles of 6% bleach (96 oz each).

Ten minutes later, just for fun, I stuck in a test strip. No FC.

An hour later, I did a test strip. No FC.

My pool is now more irritating than my teenage daughter, and believe me, that's saying something.

Any advice how I can beat this thing?
 
I have come to regard my pool as an enemy with whom I am at war.
Any advice how I can beat this thing?
Absolutely!! Call up the Reserves! (TFP) :lol:

First, Welcome to the forum!

Now, you have several issues but they all sorta center around the same idea. You are tossing in ingredient after ingredient without a clear understanding of the results. The methods taught here will give you a crystal clear pool but you'll have to change your approach. BBB is all about very careful, accurate testing and then understanding what to do about the results. Get a very good testkit. It is almost essential to your success. I have a dog in the fight in that I amke one so I'll let others suggest some possibilities for you.

Here's a couple of the issues.

1. You may well still get the CYA record. The problem is that the test are virtually meaningless over 100 so that's about the highest you'll ever record.

2. That said, loading in the dichlor as you have has probably put your CYA through the roof.

3. Partial draining and refilling is the answer but you haven't come close to near enough by draining 2400 gallons. You should probably start by draining 50% of your pool (7k) and then refill and test. Do not be surprised if we suggest you do the same thing twice. Your CYA needs to be down around 40-50 for you to manage your pool successfully.

4. Stop using Di-chlor!! You are adding I think 7 parts CYA for every 10 parts chlorine. Stop using it....it's the worst.

5. Excessive CYA is your biggest issue. Deal with that first with the partial drains, get a kit so you can test accurately for it yourself and ask a lot of questions.

You seem to have a pretty good grasp on a lot of the chemistry but you are overlooking some of the issues that improper dosing can cause. Do not try to fix EVERYTHING at once (Yeah, there's more for later).
 
What duraleigh said.

If you can just take it on faith for one month that these guys know what they are talking about.... then you will be converted because it works! And it will save you money, time, and frustration.
 
OK, so CYA may still be the issue.

I'll stay with the TFP doctrine and see how it goes. I'm out of dichlor now anyway. :)

Two questions:

1. Is it even safe to drain half my pool? I was under the impression that pools needed to stay mostly full for structural reasons. I believe my pool has steel walls and a concrete bottom, all with a vinyl liner, described here:

http://www.claytonlambert.com/

2. My family is getting impatient to use the pool. I've been telling them it's not safe until it registers some FC. Is that really true? If the BBB approach is going to take weeks, we'll be losing a lot of time. Can the kids swim? I've put in enough chlorine to kill an elephant. How many germs could be left in that water?

Thanks so much for the help!
 
Drain 1/3 to 1/2 and replace the water... re-test your CYA and see if you need to do it again (repeat until your CYA is within range).

Technically, NO it is NOT SAFE to swim. That said, it would be about the same risk of letting them swim in a pond or lake with its all-natural germ-filled water. Its a judgement call.

If you are aggressive and move to get your CYA down immediately, and then follow immediately with shocking the pool, you could probably get this back to sanitary within a week to two weeks. AND it will cost you less than any other method. Period.
 
How does the pool water look?

And I second the TFTestKit -- Good instructions, very fair price, great service and delivery time. And most of us here use that and so we can help you really quickly if you have a question. If you want to be cool you can add the SpeedStir. I won that in a forum contest (see Name your pool cleaner) and I just love it. On some tests I had to add a LOT of drops, 20 or 30 and there was a lot of swirling the vial required. ("Someone, 22, GET THE PHONE, 23, I"M BUSY, 24") Those are the tests I do maybe monthly but still, very nice to just drop, drop, drop, then BAM the color change occurs, Done.
 
I've put in enough chlorine to kill an elephant. How many germs could be left in that water?
Lershac has already answered but to emphasize, the answer is "Plenty" YOu have no chlorine left in the water. Unlike the other parameters, chlorine is consumed.

I'll stay with the TFP doctrine and see how it goes.
If you truly follow the methods taught and practiced here it will go very well indeed. Seriously.

I'm glad you're out of di-chlor!! :mrgreen: :mrgreen:
 
Re. safe draining: As long as you still have at least 1' of water in the shallow end, the liner should stay in place. So, that's the most you can drain at once; in the pool you described, that would be about half the water.
--paulr
 

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ericsink said:
OK, so CYA may still be the issue.
NOPE.. High CYA IS the issue.. Look at the CYA/Chlorine charts in Pool School and you can see how much chlorine you need at 90 ppm vs 30-40 ppm.

I'll stay with the TFP doctrine and see how it goes. I'm out of dichlor now anyway. :)
GOOD!

Two questions:
2. My family is getting impatient to use the pool. I've been telling them it's not safe until it registers some FC. Is that really true? If the BBB approach is going to take weeks, we'll be losing a lot of time. Can the kids swim? I've put in enough chlorine to kill an elephant. How many germs could be left in that water?
Lots! No FC=No killing power = germs & algae.

You will get there but your CYA has to be at a point that the excess CYA (and you DO HAVE excess) doesn't bind to all of the chlorine that you put in.

1. Drain & fill to get the CYA down to 40. Unfortunately, it's the only way to do it.
2. Add ultra bleach (6%) to bring the chlorine up.
3. What type of pump, filter, cleaners, etc. do you have?
4. Is there ANY type of organic matter in the pool? Is the bottom clean? Is the water circulating and the skimmer catching large material? Are you using a "skimmer sock" or knee-high nylon stocking to catch the small stuff?

Keep us posted!

Terry in NC (and enjoying the REAL salt water! :cool: )
 
One other thing. If you are using test strips, they may be bad. I have witnessed that first hand. Lots of chlorine, but yet shows zero using the strips. Listen to the experts here. They will get you to where you need to be. Also, the TFTestkit is the best value for your money, bar none! I hesitated buying it last year for weeks, finally decided to. My hesitation was a complete waste of time.
 
Update:

I drained about 6,500 gallons from the pool, down to 14" of depth in the shallow end.

And then I replaced that water. The pool water now has sort of a greenish tint.

I ordered one of the good test kits recommended here, but it won't be here for a few days.

I used a cheapo strip test which suggests that CYA is okay, but I'm not saying I believe it.

I bought the HTH 6-way kit test at WalMart and used it. It says the CYA is still about 100. Not sure if that means anything interesting or not.

I'm running the Polaris a lot just to continue cleaning the pool. Perhaps I should have mentioned this before, but there is a white powdery substance on the bottom. The Polaris has pulled up a lot of it, probably 5-10 pounds or so. My wife thinks it looks like sand, but it seems too fine and clumpy for sand. Anyway, when I first started using the Polaris, its bag was coming up filled with this white mud.

Tonight I added six bottles of bleach. It's only 1.27 a bottle at WalMart, and I was willing to spend 7.62 to give myself the illusion that I was doing something that might help. :)

More later. Thanks again for the help here!
 
The HTH kit (that isn't the strips) would be vastly more reliable than any strips. So your CYA is still over 100, and you need drain halfway and refill (again). Assuming your well can handle the volume.

Because of the white gunk the Polaris is pulling out, I'd say start the drain by vaccuuming to waste, even if you can't see the bottom. You'll pull a lot more of that crud out, which can't possibly hurt anything.
--paulr
 
According to the "Effects of Adding Chemicals" Section of the Pool Calculator, you have added approximately 768 ounces of Dichlor since you opened the pool, based on the info you provided, which would have raised your CYA by 193, and that doesn't take into account what the CYA level might have been when you opened.

So even if you drained out about half you still would be near 100 if not higher (since the vial stops there).

Back when I used test strips, the strips used to tell me my CYA was 30-50, when in reality it was over 100. The strips are extremely unreliable.
 
Another update:

I completed drain/refill cycle #2. This time I took it down to 12" in the shallow end. I estimate just over 7,000 gallons replaced.

The HTH kit now says CYA is just over 50. That's progress, right?
 
50 is beautiful (he said modestly :) ). It's fine to stop there, CYA will drop slightly over time by itself, so it's reasonable to start the season on the high side.

Let's see the rest of your numbers, and get them tuned up as well.
--paulr
 
Cool.

ph is 7.5
TA is 360

I'm guessing that TA level is too high. Do I need to fix this somehow before I shock?

And by the way, after a night of running the filter, the water looks amazing. It's almost clear, even though I haven't added any chemicals since the second cycle of drain/refill. I'm guessing this is simply because the extremely high CYA level was making the water cloudy?
 

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