Zero Chlorine

[Rockforce]

Hey all, found this site as a result of googling the issues I've had a with a new (to me) pool. I have absolutely no idea what I'm doing regarding pool stuff, but I recently read through pool school and am trying to get started on the TFP method. Grateful for any help you guys can give me. I'll try to be brief but the main issue is I have not been able to hold any chlorine, appears CYA levels are over 100 even after draining.

When I bought the house, pool looked fantastic and took care of it based off previous owners and pool store advice. All looked well, but I wondered why there was very little to no chlorine. Pool store continually told me it just needed more bags of shock, only answer for why it wouldn't hold was that the chlorine gets burned off by the sunlight. It gets sun virtually all day long. I didn't question their sage advice until I ran into an article from this site saying to use liquid chlorine. So I started doing that without understanding the method. I added a gallon of liquid chlorine (from a pool store) once a week. It would shoot the chlorine levels over 10 on my Taylor test kit, but be back to zero within two days. I assumed that would work well enough and did that method for a couple months.

Last month, started having small algae spots, put in more bleach and more and more. Went up to 3 gallons in a couple days and it registered zero when I tested it, which is when I realized there had to be a bigger problem. Water started to get pretty cloudy. Got the water tested at Leslie's, they said CYA was high (200) and that the pool needed to be partially drained. They also said not to use liquid chlorine because that will raise the CYA when its all burned off, while their shock brand won't. That registered as weird to me, which is what led me to actually read through pool school and attempt to fix this.

I read some different threads here and decided to drain a good portion of the pool and refill. I drained about 80-90% of the pool and then refilled with a mix of softened and tap water. After refilled, I tested the levels and added a gallon of bleach.

Numbers:
FC = 1, TC = 1
Ph = 7.8
TA = 200
CH= 250-275
CYA = well over 100 still. When testing, the black dot was no longer visible at about half the way from the 100 mark to bottom of the tube.
Pump runs 10 hours a day.

So I'm at a loss for what to do now. I thought draining would fix the CYA, which means there's something more that I don't understand. I even tested it twice to be sure I didn't screw it up. Did I screw something up on the drain? Instead of shooting in the dark, I figured I'd let you guys set me straight.

Thank you for your help,
Eric

 

[YippeeSkippy]

Eric, welcome to TFP I'm sorry you're having these problems but lets see if we can help you clear up.

First you need to understand that Clorine (Free Chlorine) is consumable. SO every day the sun will take some away if you let it, or by a kid's pee if they make a deposit, or by algae its trying to kill. So one needs a stead, daily dose of chlorine.

How you get that chlorine in the water is up to you-

How to Chlorinate Your Pool

Before chlorinating your pool, you should know these simple tips. Learn the best way to add chlorine to your pool.

www.troublefreepool.com

So you put that chlorine in there but you want to "protect" some from the sun so its available. We do that with a specific amount of CYA stabilizer. You put too little in and the chlorine burns off and it won't be available to work for you. You put too much in and there is so little "un-bound" in stabilizer to be available to attack the cooties you need more-and-more just to attempt to make a dent. Sooooo... too little is bad, too much is bad. SO how much do you want?????
Well.... if you're going to use liquid chlorine your level should be lower than if you use a Salt Water Generator (SWG). That's because when using liquid you're giving the pool a big blast of FC at one time, but with the SWG its feeding your pool little continuous doses that need to be protected.

The Free Chlorine and Cyanuric Acid Relationship

Managing your cyanuric acid and Free Chlorine levels is key to stabilizing your pool. Learn how these two items affect each other.

www.troublefreepool.com

So it sounds like you still have a mess of CYA in the water? How are you testing this? Which test kit??

I'll wait for that answer before continuing on.....

Maddie

 

[red-beard]

One problem with testing for CYA, the test is only good up to 100. Above 100, you must dilute the sample. Generally, for the CYA test, using tap water for diluting is fine. I prefer a "macro" dilution. Mix 16 oz of tap water with 16 oz pool water. This way, small errors won't affect the results.

 

[Dtkokay]

Sorry to hear about your problems, and it’s the most common one I see here. Out of control CYA.

One key thing to understand is that once you add CYA to a pool, it pretty much stays there. It can be slowly decrease (and I mean SLOWLY) by rain or the sun. On the other hand, chlorine burns off quickly and must be constantly added.

That’s the problem with tablets - they have both CYA and chlorine. The CYA keeps building up and the chlorine does not. Next thing you know, you have so much CYA in the water that the chlorine is rendered ineffective.

As mentioned above, do a diluted CYA test because you’re still over 100. Drain the pool enough to get the cya down to the 30-50 range, and then use liquid chlorine. You’ll have to add liquid chlorine every day. Or you can go back to tablets with the understanding that you’ll have to drain periodically to keep the CYA in check.

Your chlorine level depends on your CYA level. Follow the chart in the Pool School / ABC’s section, and it’s better to err on the side of too much FC.

In short, get that CYA down and KEEP the chlorine level up by replenishing every day.

 

[Rockforce]

Thanks for the quick responses everyone!

Maddie,
I’m using the Taylor k2005 test kit.
I’m on board with doing liquid chlorine everyday to keep the levels up rather than messing with this cya problem frequently.

I’ll try the diluted cya test to get a better idea. But that being said, it’s still far outside the recommended limits. Which means I need to drain again? I just refilled it so I guess I’m a little confused that it’s still so high.
Is this common, to drain 80% and then still have that high of cya levels, or could there be another issue?

 

[CrystalRiver]

If you drained 80-90% and your levels are still over 100, they were way over 200 before your drain. That's not uncommon, though unfortunate. Yes, the only solution here is another drain of most of your water.

When you drain, aim to drain too much rather than too little. It's easy to add back CYA if you get it a bit low. But if it's still too high, the only options are deal with it (additional chlorine) or do another drain.

 

[red-beard]

Is this common, to drain 80% and then still have that high of cya levels, or could there be another issue?

I used Trichlor for 7 years before my first drain and refill. I suspect I had near 1000 ppm CYA. This is why the dilution test is important. If you actually are now at 100 and you drained 80%, this would mean you originally were around 500 CYA.

 

[Newdude]

When you drain, aim to drain too much rather than too little. It's easy to add back CYA if you get it a bit low. But if it's still too high, the only options are deal with it (additional chlorine) or do another drain

+1. This is the perfect instance of that. To get to 50 from 500 it’s a 90% drain once. To drain 80% and have 100 they will now need to drain 50% to go from 100 to 50. So either a 90% drain once or a 130% drain over two times makes the same result.

 

[Chasarms]

Each 8 oz trichlor puck is adding a little over 3 ppm of CYA to a 10k gallon pool. So with a fresh fill, if you use five a week for a 30-week pool season, you’re at 450 by the end of the season. In reality, it is probably more like 350-400 due to splash out, overflow and degradation. But, in year two if you open over 300. And keep using trichlor..? You get the idea.

Just keep diluting the pool water sample until you get a reading within the range of the test.

If one part tap water to one part pool water still tests over 100, then try three parts tap water to one part pool water and multiply by four for the correct test value. If you still test over 100 after an 80% drain and a 3:1 dilution, you don’t have a pool, you have a CYA storage tank!

 

[Lilypad]

It took this website and 2.5 drains to get my CYA in range years ago. Tabs and the bags of shock all add CYA at an alarming rate if you are unaware of it. Most of us got here because of the same issue! Post what you are doing with reliable test results. Ask before adding chemicals to the pool until you get a good grasp on things. You'll be amazed how easy and much less expensive it can be to manage your pool. You are in the right place. Welcome!

 

[YippeeSkippy]

Ok... you need to upgrade your K-2005 test kit with the addition of this test---> FAS/DPD Chlorine & CC's test
That will bring your test kit up to the standard K-2006. That FAS-DPD test is probably the most important test you need as it will read your FC and CC levels at a much higher rate than the simple comparitor block test for FC.

Maddie

 

[YippeeSkippy]

We hear time and again from folks how shocked they are when they realize how high their pool's CYA is. Some folks out your way also deal with high calcium and just plan on a bi-yearly drain and refill to deal with these issues.

Maddie

 

[Rockforce]

WOW! Ok, thank all of you guys. I’m starting to get the picture a little more clearly now. I wrongly assumed I was at 200 because that’s what the store told me. It’s far more likely that I was way above that like red-beard described. The pools probably had hundreds of those pucks, since that’s mostly what the previous owners used.

So I’ll do the diluted test and drain another large portion of the pool. Going to have to wait for my billing cycle as I’ve crossed the line to double pricing at the moment. I’ll also pick up the extra tests suggested.

It seemed pretty insane at first but this has demystified it a little bit to me. I have an idea how to move forward and fix this. And fix my hot tub that has similar issues.

I am left with the question, why does anyone use chlorine that raises cya so much? It seems ludicrous to do that and have to drain every couple years. But that’s really all anyone recommends. I’m sure that questions been asked a lot on here.

Thanks again for all the info. Doing this on my phone so sorry I couldn’t do the normal quoting and responding as seems to be common here. I really appreciate all you taking the time to help.

 

[mknauss]

The draining every couple years (and it really should be done more more often than that if trichlor is used) is actually the least of the issue. The fact the pool is just not sanitary is the first thing. Person to person disease transmission, etc is far worse as the CYA gets above 100 ppm and the FC is still at 2 or 3 ppm. Then the harshness of the pool water. Most people have no idea how pleasant a swim in a pool managed using TFPC parameters is.

 

[Momma4]

Hey, Rockforce, I just wanted to encourage you and let you know you’ve found the right place.

I found this site recently by googling a problem that I was having, and my pool is now a sparkling beauty by following TFP methods. I wish I had found this site sooner!

so, hang in there - I’m sure your pool will be cleared up in no time!

 

[red-beard]

Momma4 is right! This is the place and the easy methods outlined here work!

I think Trichlor is convenient for CERTAIN seasonal pools that are drained every year. These are farther north, and don't need as much chlorine additions. In the areas with year round pools, with extreme sunlight, trichlor is a disaster waiting to happen.

But but but this is what my builder said. And my pool store. And the guy down the street. They have had pools for years. They can't be wrong. But they are. all of them.

 

[Rockforce]

This system does seem pretty simple, especially with a community like this behind it. It kind of amazes me that with all the pools out here in AZ, I hadn’t heard of this method before. Everyone seems to just pay someone to take care of their pools. I’m definitely looking forward to being able to hold chlorine and have an intelligent process behind managing the pool. I’ll be passing this site on though.

Results from the diluted test show me at 300 cya. Using the calculator, I’ll do another 80-90% drain and should be around 45 cya. I may go ahead and drain the hot tub as well since cya is high there too and from reading on here, liquid chlorine is fine to use there as well, once the cya is in range.

That will take place in a week or so once water billing resets. I’ll verify the level and then start the SLAM process. From there TA was the only thing outside of recommended levels.

Last time I just used the pump to drain the pool. Is there any issue with doing that? It seems to work just fine, although I’m guessing it’s not exactly meant for that.

 

[mknauss]

Last time I just used the pump to drain the pool. Is there any issue with doing that? It seems to work just fine, although I’m guessing it’s not exactly meant for that.

Draining - Further Reading

www.troublefreepool.com

I would suggest getting a 1/2 hp sump pump. I tend to not use a $1000 pump when an $80 one will do the job. Of course, if you actually drain, then renting one from Home Depot can drain your pool in about 3 hours.

 

[Rockforce]

Thanks for that suggestion. Makes sense not to use the pool pump for this. Picked up a pump and will start the process tomorrow.

Re read through the SLAM and just wanted to make sure I’m understanding properly. The goal is to maintain shock level FC the entire time correct? So every time I test, I add to bring it back up to the shock level, even if it’s one ppm off. Keep that level until I don’t lose 1 ppm FC overnight.
Time of day (direct sunlight or not) to add chlorine is irrelevant during SLAM, correct?

I will only be able to test twice a day with my work schedule. Pool gets direct sunlight for about 10 hours a day, starting about an hour before I get up. That being the case, is there anything additional I should be mindful of when testing / adding chlorine?

thanks again.

 

[mknauss]

You are correct about the SLAM Process

If you can only test FC and dose twice each day, the process will take a long time. Are you not able to attend to it in the morning, right after work, after dinner, and before bed? No one available to add some chlorine mid-day?