Where is my chlorine going?

[vanman2501]

My numbers are good, my pool is crystal clear but my chlorine is 0. I shock it at night and the chlorine reading is high and by morning the chlorine is back to 0. This has been going on since I opened the pool over month ago. I tried shocking a few time a day for a few weeks then finally gave up and for the past three weeks have just kept chlorine tablets in my floater and the pool is still the same. Good numbers except the chlorine and crystal clear. Where is my chlorine going?

vanman2501

[Watermom]

We'll need a little more info to be able to help. Post current water testing results (FC, CC, TC, PH, alk, Calcium hardness, cya) and what type of kit you tested with. Also, tell what type and volume your pool is and exactly what all you have added to your pool. (Ingredients, not just "shock", etc.) Then somebody here can take a look and hopefully help you figure out what is going on.

[vanman2501]

My numbers are
TH - 20
FC - 0
PH - 7.5
TA - 120
CYA - 45
I have used a few different testing kits the HTH test kit, the HTH test strips and another liquid test kit the I can't remember the name of. All have the same readings
I have a 24' round 52" deep above ground pool.
I use borax, baking soda, liquid bleach and chlorine tablet.
Since I changed to using these products I have never had a problem until this year.

vanman2501

[Watermom]

In a pool this size, each quart of 6% bleach should raise your cl by about 1 ppm. How much bleach at a time are you adding and how often? Go ahead and add 6 quarts (1.5 gallons) and that should take you up to 6ppm. What type of chlorine tablets are you using?

[vanman2501]

I use pro-care 3" pucks
I was adding one and a half gallons then went to 2 gallons and then went up to 3 gallons and I'm back to one and a half gallons. No matter how much I added I always end up at zero in the morning. I just added one and a half gallons so I see what happens in the morning again.

vanman2501

[tonyl]

You might have your water tested for phosphates. If they are 3000ppm+ as I suspect, it will consume the chlorine quite rapidly. I've been there and have to treat every 3 years or so. Not many people have this problem, but phosphates build up in my pool and I find it impossible to keep chlorine in the water more than a few hours when I let them go. Sounds like that's what you have going on to me.....I use ALUM when it gets that high, kinda messy...have to vacuum to waste after treating but it's effective.

Hope this helps, Tony

[CarlD]

I'm sorry but this is a VERY simple problem. Something is consuming your chlorine and you have to KILL it.

You need to shock your pool (with bleach) up to 15ppm of Free Chlorine (FC). You have 13,500 gallons. That means you need to add 3.5 gallons of Ultra bleach to get it to about 15ppm. Or you can add 4 gallons of regular bleach.

But you have to do it. Then, 3x a day, check that the FC is still in the 12-15 range. If not, each gallon of Ultra will add 4.4ppm and each gallon of regular will add 3.9ppm.

You need lots of bleach and lots of P.O.P.P.--Pool Owner Patience & Persistence.

You have absolutely NO reason to suspect or treat phosphates. Phosphates are the LAST test you do, when you have exhausted all the other steps. But you need to start with the first one--you have something you MUST destroy so you can maintain your chlorine levels. I've told you how to do it. It's not easy, but it IS simple.

[tonyl]

No need to be sorry, it IS a simple problem and we both agree that "something is consuming your chlorine."

I was simply sharing my situation relative to phosphate buildup that I've experienced several times in the last 9-10 years of pool ownership. I could have shocked for weeks and the problem wouldn't have gone away. Like vanman, I was unable to maintain chlorine leve within the pool. And this situation repeated itself AFTER installing a SWG (chlorine level 100ppm within the cell) virtually eliminating routine shocking.

Your assertion that "you have absolutely NO reason to suspect or treat phosphates" is not clear for me, considering I advised he 'might have his phosphates checked", and it's exactly what I've experienced with my own pool the last decade.

Given my history, what harm could be done by a free phosphate test?

[CarlD]

Phosphate testing seems to be the latest pool store scam to get people to buy expensive chemicals. Phosphate removal is a last ditch effort. Maybe one in a thousand pools requires it. Many of our members have a heart attack when they find their phosphates are high, but following our methods their pools stay clear, clean and sweet--WITHOUT removers. So why bother testing for them?

You go through ALL the steps for clearing your pool first before you go to phosphates. This starts with proper chlorination, proper shocking, patience and persistence. If, after a couple of weeks of PROPER algae clearing techniques your pool is still cloudy, you look to other causes and treatments.

Finally, after ALL of them have failed, you test and treat for phosphates. This is, as I said, one in a thousand.

Respectfully, I suspect that if you follow the standards for chlorination established here, you won't have problems and you won't need phosphate removal chemicals--unless you are that one pool in a thousand.

[VOLDADDY]

vanman,

I had the same issue you are having now when I opened my pool. You can look back at my thread entitled "Excessive bleach consumption" and see all of the information I was given. Carl hit it right on the head...you have got to hammer it with bleach. I did 3x a day to get to 15 ppm and it took almost 2 weeks before whatever alien life force that invaded my pool died off. Now I'm on cruise control and add a jug of bleach every 2 days, and my pool looks great. Good luck, as I know first hand how frustrating this can be. I tested when I got home from work and bumped to 15 ppm, then before bed and bumed to 15 ppm, and on the advice of others I would even add an extra jug about an hour later, then in the morning I would test again, bump to 15 ppm. If you are losing chlorine from the bedtime reading to early AM reading [before the sun hits it] then you have something you don't want in the water eating your bleach. Do you have any CC in your pool? The weird thing about mine was I had 0 CC.

[ShelleyAnn]

Voldaddy - How did your liner survive the barage of chlorine?

[goosegunner]

So when you maintain this high chlorine level is your pool out of service for swimmers for 2 weeks then?

Again what about your liner?

I just found a small 1/4" cut in our 5 year old liner. When I went to the pool store to get patch glue the woman at the pool store told me to watch the Cl levels because too high will cause that. I have never ran with high Cl other than shock.

gg

[CarlD]

"too high" depends on the level of CYA in your water--stabilizer. With none, vinyl can tolerate up to 15ppm of free chlorine. But with stabilizer slowing down the chlorine, you can go higher--see the Best Guess table for the shock levels--they apply to vinyl pools.

[vanman2501]

Well my chlorine has been dropping but not to 0 it goes down to 1 & 2 and holds there that's a big improvement. Maybe what ever is causing the problem is just about gone.

vanman2501

[vanman2501]

I did a full test of the chemicals and found my ph dropped to 7.2 and my th went to 200 but is holding chlorine between 1 & 2.

vanman2501

[Watermom]

With a cya level of 45, letting your chlorine level drop to 1-2 is not adequate to keep algae away. You have to maintain the cl between 3-6 all the time. If you let it drop below that, it is an open invitation to algae. I would shock it back up just to make sure that something isn't starting as a result of the low cl you have had.

[vanman2501]

Your right my chlorine is too low but after shocking it the chlorine was dropping to 0 and now it drops to 1 & 2 so for me that's a big improvement. This morning it any dropped to 3 so it's getting better. I still don't what is causing the large chlorine consumption but it does seem to be getting better. at this rate it should be holding a good number by the end of the season. So far I have used three times the chlorine I used all last year.

vanman250

[vanman2501]

My pool is finally holding the chlorine level at 6. Since I opened my pool I have been dumping tons of chlorine in my pool and it would disappear then it started to rise a little every few days and now it's finally holding where it should. Thanks for all the help.

vanman250