Having Issues with Chlorine Levels - Please Help

Dec 7, 2011
40
Naples, FL
Hello,

I am having some issues with keeping my Free Chlorine levels up and I can't figure it out.

Sorry for the long post in advance, but I want to make sure I provide all the details.

My problem started this week at the beginning of the week. My free chlorine levels would be almost 0 in the mornings...basically from 0.5-1 and I normally keep them at around 4ppm

I used to use about 1 gallon of 11% liquid chlorine every week to keep that level.. and it would drop maybe 0.5-1ppm at most each day...and this was for the past couple months roughly.

Last week was the first time we ever used the pool (just moved into house few months ago, and finally got it heated with the new solar) and we used it every day for 7 days straight. I kept the levels at 3-4ppm all week..using above average amounts of chlorine which I assumed was due to the use of the pool and higher temps (84* water temp).

SO this week I check it in the morning a few days ago and it is at like 0.5ppm..so I added half a gallon to raise it up to 5ppm according to the pool calculator.

So thinking nothing of it I check it the next day and again it is only at 0.5 even less maybe. I checked it 3 times and same result every time. (and yes I have a professional Testing Kit, not strips)

So I got worried and added another 1/2 gallon, only to have same result the next day. Yesterday I realized I hadn't checked my Total chlorine levels...so I did and found them to be 1.5ppm over my free chlorine level. I thought this was bad, so I shocked the pool with 2 gallons of liquid chlorine, which should have brought it over 20ppm, and I thought that was supposed to burn off any combined chlorine (the bad chlorine is what I am told) and get my levels back on track.

Move on to today, and my free chlorine is only at 5ppm and total chlorine looks to be about 6ppm so still higher...it's like the cholrine I am using is 75% water or something, and I have used 3 different containers of chlorine so I know it's not a bad container of it...it just makes me scratch my head.

My Cya Levels are at 45ppm, and all my other levels (PH, ALk etc..) are in the correct range, so where the heck is my chlorine going suddenly?

I am going through chlorine like crazy and it's getting expensive! I am not sure what to do so figured someone here must know what I am doing wrong or what my problem is. Do I need to keep shocking it until this stops?

Any help would be greatly appreciated.

Thank you
 
It sounds like you have an algae bloom starting. With a CYA of 45 you should have never let your FC get below 4 ppm.
Post a full set of test results.

With a CC of 1 ppm or more you need to shock the pool. Remember that shocking is a process and not a one time event. You have to add enough FC to get to your shock level (20ppm FC) and then test and add as often as once an hour in the beginning to keep it there until you pass the OCLT (see sig).

Your problem is that you're adding chlorine but you're not maintaining shock level and the algae is catching back up. It's a one step forward, two steps back kinda thing.

Once you've shocked properly and passed the OCLT you'll be surprised how easy it is to maintain the proper FC for your CYA.
 
Awesome thank you.

Here are my results as of this moment and I found something else I wasn't aware of as of lately. (ALK is really high)

Last time I tested ALK was about month ago and it was ok. (didn't think this was important as far as my issue, but maybe it is)

FC: 5ppm
TC: 6ppm
PH: 7.6
ALK: 400+ PPM..highest mine goes is 400 (what could cause this high number and what do I need to do?)
Hardness: 200ppm



OH ya I also wanted to add that we had a recent Pollen outbreak from the trees here...tons of pollen..could this have caused the algae?
 
If you can't see algae in the water, it doesn't mean it is not in there. Last year I was going through the same process as you, then I found this site and properly shocked my pool and I haven't had any problems with holding chlorine since. Bama is right on and just follow his advise.
 
The only problem with that kit is that you can't measure the FC high enough to effectively shock the pool. It only measures to 10 ppm FC. You can add a FAS-DPD test to that kit and it'll be good to use. Lamotte has one or you can order just the FAS-DPD test from tftestkits.
 
Ya that is the only thing I don't like about it.

I will have to make due for now, as I can't wait to get my pool taken care of on a test kit.

I just checked and it was showing 10+ppm plus I added another gallon of chlorine after that, scrubed down my walls, and will run the pump all night. I will just have to shock it for a several days and hope for the best. I used this kit the last time I had an algae problem and I got through it then so we will see I guess.

Thanks for all your help. I will be sure to update on my progress. It's a shame I have to do this, being the water is Sooooo nice right now and we wanted to use it this weekend. The water is crystal clear too, so that makes it even more annoying that we can't use it :(
 
If you going to use the DPD test for now (I agree with Bama get a FAS-DPD on order), then I would do a dilution to test. If you are shooting for a minimum of 16 ppm do a 50% dilution and look for the DPD to indicated 8 ppm or higher. Use distilled, DI, or RO water to do the dilution (city tap water usually has some chlorine).
 
Technically, it should be safe to swim up to shock level, which is 18 for CYA = 45. The real problem is that you cannot know for certain what your FC level is once it reaches 10 or higher. Agreed that dilution will allow you to test higher levels, but remember that the accuracy will be proportionately less, ie., 50:50 dilution gives double the scale, but half the accuracy.

As a note, there are basically two reasons to lose FC in a pool. One is loss to UV rays from the sun, and the other is loss to organic matter in the water. If you are losing FC at night, when the sun is not on the pool, you have organics in the water. And these organics will consume chlorine as the chlorine tries to kill it. The enemy has reproduction on it's side, and it will constantly be bringing new warriors to the battle. Chlorine depends on you to add more soldiers to it's army as it's soldiers die in the battle. You need to raise the chlorine level to the point at which it is pushing the enemy back (shock level based upon CYA) and maintain it long enough to fully eliminate the organics in the water. When the overnight loss is zero, the battle is pretty much over.
 

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Wow, all great info guys thanks a bunch!

I will do the dilution test..I was just talking to my Dad about that and we weren't sure if you could do that, and then I come on here 30 seconds later and thats exactly what you guys suggested haha.

While I am on the topic of Algae, Has anyone heard of or used something called Lo-Phos?

The guy that takes care of my parents pool down here in FL (they live in MN so they have someone who takes care of it while away) said he uses this thing called Lo-Phos in all his pools and hasn't had an algae in the 6 years hes used it. Just wanted to see your thoughts, comments on this.

Thanks again for all the help, this site is the best!
 
Phosphorus remover is the newest pool snake oil. And here's a forest fire analogy to help explain it all:
Basically, it removes algae food, which is like removing wood as fire management.
In a properly sanitized pool, there will be no algae, and phosphate concentration will not matter. Which, in fire management terms, is like not having a fire.

Phosphorus remover will lower phosphate levels, but it's specialty is removing money from your bank account.
 
Ohm_Boy said:
The enemy has reproduction on it's side, and it will constantly be bringing new warriors to the battle. Chlorine depends on you to add more soldiers to it's army as it's soldiers die in the battle. You need to raise the chlorine level to the point at which it is pushing the enemy back (shock level based upon CYA) and maintain it long enough to fully eliminate the organics in the water. When the overnight loss is zero, the battle is pretty much over.

a forest fire analogy to help explain it all:
Basically, it removes algae food, which is like removing wood as fire management.
In a properly sanitized pool, there will be no algae, and phosphate concentration will not matter. Which, in fire management terms, is like not having a fire.

You HOT tonight Ohm_Boy! ::epds::
Love the layman's stories!

Chuck
 
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