Losing chlorine

Hello all, I wanted to give you guys an update on my pool. I finally got my ph up to normal range 7.2 and it's been holding steady. However, I'm still losing huge amounts of chlorine every day. For the past few days, I check in the morning and my levels are the following
cl - 10+
fr cl 10+
ph ~7.2
tot alk 120
Cyanuric acid 100

At 6 pm The Cl and Fr CL go to zero and other levels stay the same. So I add shock and the levels go up. This process has been the same for about 5 days. Any thoughts?

I use 3" tabs in my chlorinator (5 tablets) and I run filter for 8 hours. The setting on the Chlorinator is maxed out. Last year, I think I used 3 tablets and ran filter for 4 hours and that was fine. Bottom line, something is eating my chlorine. Any help would be great. Thanks.

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Originally Posted by joecus

Hello all, I wanted to give you guys an update on my pool. I finally got my ph up to normal range 7.2 and it's been holding steady. However, I'm still losing huge amounts of chlorine every day. For the past few days, I check in the morning and my levels are the following
cl - 10+
fr cl 10+
ph ~7.2
tot alk 120
Cyanuric acid 100

At 6 pm The Cl and Fr CL go to zero and other levels stay the same. So I add shock and the levels go up. This process has been the same for about 5 days. Any thoughts?

I use 3" tabs in my chlorinator (5 tablets) and I run filter for 8 hours. The setting on the Chlorinator is maxed out. Last year, I think I used 3 tablets and ran filter for 4 hours and that was fine. Bottom line, something is eating my chlorine. Any help would be great. Thanks.

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I am going to make a guess that you are constantly fighting a nascent algae bloom because of your high CYA and that is what is consuming your chlorine. also, how are testing because there is NO reliable way to test for high C>Ya levels and there is a very good chance your CYA is actually higher than 100 ppm. The fact that you continue to use trichlor means that your CYA is continuing to climb since trichlor adds 6 ppm CYA for every 10 ppm FC it adds.

If it were my pool with a cya reading of 100 and who knows how high it actually is (like Waterbear said, can't differentiate between 100 and >100), I would do a partial drain and refill and try and get the cya down to a more manageable level. Depending on high how your cya actually is, it could take a couple of partial drains and refills. I think I would drain about 1/2 or maybe 2/3 of the water and refill and then retest and see what the levels are then. Just my opinion. At any rate, regardless of whether or not you decide to do a partial drain and refill or not, you should NOT use any more trichlor. No dichlor powder either.

If you decide not to drain/refill to lower the CYA, you are going to need to shock the pool to overcome the bloom that's trying to happen--but with your CYA that high, you're going to have to raise your Cl to 25 ppm to get to an effective "shock" level. Once the pool has been shocked, you can let the chlorine drift back down again, but it's going to have to stay at 8 ppm or above for the rest of the season in order to not risk more problems. That's why Watermom is suggesting the partial drain and refill--to lower that CYA so that your Chlorine levels are more manageable.

Janet

I'm sorry I don't understand. I am getting the cyanuric acid reading from the strips that turn color when you dip it into the pool. The cya reading I get is in the "ok" range at 100 ppm. Also, you mention trichlor, what is that? I've been using shock, chlorine tabs and sometimes bleach. Is that what you are referring to?

The chlorine tabs, if they're the kind that you use in a feeder, are trichlor--a form of chlorine that also contains CYA. Depending on what you're using for "shock", it's probably dichlor, which also contains CYA. Continued useage of those is why your CYA level is so high. In addition, strips are notorious for not being very accurage, so you never really know for sure how much CYA you actually have.

What the strips don't tell you is that a CYA level of 100 is "ok" IF you run your pool with a FC level of 8-15 ppm and shock up to at least 25 ppm. If you let your chlorine get below 8 ppm, you're asking for algae blooms and unsanitary water. Take a look at the "best guess table" stickied at the top of this forum--you'll see that as your CYA (stabilizer) level increases, so must your base chlorine level in order to keep your water clean. So with your CYA as high as it is, I certainly wouldn't use anymore trichlor tabs or dichlor shock--I'd switch to bleach, which won't raise your stabilizer anymore.

I also would encourage you to get a test kit of your own that is drop-based, not test strips. A good kit is key to managing a clear, clean pool with very little effort. AT the very least, I would advise you to either take a sample to the pool store to be tested by the reagent method or even to go to WalMart and get the 5-way test kit (which includes a CYA test) and test it yourself.

Eitherway, you're either going to have to up your chlorine to compensate for the high CYA levels, or drain/refill part of your water to lower them, if you don't want to fight your pool all summer.

Janet

OK - I just ordered a 5 part test kit. My plan is to switch to bleach until I can determine an accurate cya. At that point, I will drain if necessary. Can someone explain how my pool can be unsanitary right now? Both fr cl and cl are so high, can I use pool?

I don't trust strips CYA reading. My Hache strips are indicating I have no CYA but the Taylor black dot test indicates it's just under 50ppm. Either I'm reading the strips wrong or the CYA test is wrong. The chlorine tests aren't too bad and I can usually use the pH test safely.

But the CYA, CH and TA tests are worthless. I check 'em anyway so I always know what owners see when they use them.

Is my pool safe to use? Someone mentioned it is unsanitary.

You can use the pool if you're keeping your chlorine between 8-15 ppm, with your CYA at 100. Test for combined chlorine, and if it's less than 0.5 and the pH is between 7.2-7.8, then it's fine to use the pool.

If your chlorine is still higher than that, I would feel ok with using the pool with chlorine levels even up to 15 (this is because the CYA is so high), but I would wear an old suit in case of fading.

If you test the water and have CC greater than 1, or if you've been running the pool for more than a few days with a chlorine level less than 8, then I wouldn't swim in it.

Janet

Thanks Janet and Watermom. - I've decided to empty the pool right after the holiday. I can't get the cya and ph stabilized. Any recommendation on the refill? Do I need to scrub the liner when it's empty? Anything I need to watch when I empty it?

You do NOT want to totally empty a liner pool or you will ruin your liner. Do a partial drain and refill (maybe 1/2 to 2/3 of the water) which will get your cya level down to a more manageable level, but do NOT drain all of it!

Did you get the kit you ordered? What kit is it?

You haven't posted a complete set of current water testing results for several days. Can you do that, please? Also, please list exactly what all you have put in the pool -- meaning ingredients, not just "tabs" or "shock."

Ok - I got the kit taylor 2005. I just ran the tests and here are the results.
fc 5
tc 5
ph 7.8
alk 120
ca 70
cya 100+
As far as ingredients, I started the year using, powder shock with the 3" tablets. When I started losing chlorine I added about 4lbs of cyanuric acid. Then I added a algaecide to stop the chlorine loss.
Once I realized my ph was too low, I started adding borax, I would guess 15 boxes up to this point. Then I realized my cya was too high so on Tuesday, June 30, I emptied half the pool and refilled. I've been using bleach only for about a week. I'm checking the chlorine very often and adding bleach as needed. So, what do you think? Thanks for your advise.

So even after draining half, you are still at CYA over 100? Wow! You will have to either do one of two things:
-- Do another drain and refill of 1/2 to 2/3 water again to try and drop cya further or
-- Run higher than normal chlorine levels to compensate for the high cya. That would mean that you would have to keep your cl between 8-15 ALL the time and when you need to shock, you'll have to take it up to 25.

You need to get some bleach in there and bring your cl level up ASAP.

No more tabs or powder shock for your pool as they both have cya in them and yours is WAY high. Stick with bleach.

How does the water look?

The water looks great. My cl and fr cl are both at the max on the scale in the taylor kit. I must be using the kit wrong since I only see a 5 at the top of the "cl" and "10" under the bromine column.. You mention keeping the levels higher, how do I do this with the kit? How do I differentiate the higher numbers?

The "shotglass" method is here: Take one part pool water and one equal part distilled water and mix these together. Run your test with this water and then multiply your result by 2. If that doesn't take it high enough for you to get a reading, use one part pool water and two parts distilled and then multiply by 3, etc. (The dilution method does lose accuracy with each dilution but it is better than nothing when you have no other way to get a reading with such a high cl.)


This will help you force your kit to test higher chlorine numbers than 5 ppm. I agree with Watermom, if you've already replaced 1/2 your water and STILL have a CYA of 100+, there's no telling how high it actually was. Rather than drain it all, just drain another 1/3-1/2 like Watermom suggested, just to drop it down into manageable ranges.

Or, as an alternative, you can just run your normal chlorine no lower than 8 ppm, staying in the 8-15 ppm range. It's hard to do, though, consistently.

I absolutely would not use anymore trichlor pucks or dichlor to shock--definitely only bleach if it were my pool!!

Janet

Hello all, today I emptied and replaced 1/3 of water, cya didn't move and is still way above 100. Is there anything else that could be causing this? I've been using bleach only. How much water can I safely remove without destroying my liner? Thanks

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Hello all, I'm really baffled. Like I said, I've been using bleach instead of chlorine and my cya is still going up. I just looked at the bleach bottle and it is brand name "Home Basics". I can't find any percentages to determine the strength. However, I did notice something I found suspicious. It states, "contains sodium hypochlorite", "contains no phosphorus". Can that sodium hypochlorite be raising my cya? Please help. Thank you very much.

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OK, sorry for the previous post. Bleach = sodium hypochlorite. So, I will push forward with another partial drain. What is the ideal cya? Can anyone recommend a place to get refills for my test kit? I'm going to need r013 soon.

Hi Joe;

Sodium hypochlorite adds sodium and chlorine to the pool, but no stabilizer (cyanuric acid, CYA). However, you need to find a bleach that shows % -- should be around 6% sodium hypochlorite. Some highly dilute bleaches are sold 'cheap', but are actually a rather bad deal.

Regarding CYA and draining, with most kits it's very hard to accurately measure CYA levels above 100. In other words, your level could have been 300 ppm and you may have now reduced it to 200 ppm . . . but it would 'test' the same. If you do a 1/3 drain again, you'll reduce (hypothetically) that 200 to 130 or so, and STILL look pretty much the same.

As to how far you can safely go, without knowing more about your pool, I can't tell. If you want to take some pictures and email them to me, I'll post them and reply. (poolforum AT gmail DOT com)

Ben
"PoolDoc"

The pool is crystal clear and I'm keeping the chlorine up high. I know my ph will change when I do a refill but why else would it go down. I'm having trouble keeping the ph up, it drops to low 7's, I add borax and it goes up to good range. Still losing a lot of chlorine. If I have an algae trying to bloom, would the high cya reduce the effectiveness in the bleach killing the algea?

You'll have to shock really high if your cya is high to do the same job as a lower chlorine level in a lower cya pool. But, as long as you get to shock level, the chlorine will kill the algae. Not sure why your pH is dropping. Have you added anything other than bleach to the pool?

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Originally Posted by Watermom

You'll have to shock really high if your cya is high to do the same job as a lower chlorine level in a lower cya pool. But, as long as you get to shock level, the chlorine will kill the algae. Not sure why your pH is dropping. Have you added anything other than bleach to the pool?

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Wow, it's so hot. My power just came back after 24 hours out. No sleep last night. I was in the pool at midnight, 3am and 5am. Today, my ph is 7.8. I am not doing the refill until the weather breaks here in NYC. I will keep the CL high to compensate for the high cya. I will let you know if the PH drops again. Does the filter play a role in killing the algae? I've been running it about 12 hours a day.

The filter's role is to remove the dead algae from the pool after the chlorine has killed it. Wow, hope your power is on to stay now!!
Janet