Burning Tons of Chlorine and Yet Have High CYA Levels...

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M

mauidad

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LifeTime Supporter
Aug 2, 2007
9
Paia, Maui, HI, USA
New to the forum and pools. Been a swimmer all my life in pools and the ocean, even a lifeguard but never had pool maintenance as a responsibility. So forgive my complete ineptitude... :oops:

I bought a house with an old pool (25+ years). Purchased from a widow who did very little upkeep. I live in Maui and we have two kids who love the pool. They are in it at least 2x per day. Here are the specs on the pool:

- approx. 25k gallon kidney shaped
- in ground.
- plaster pool (old and needs to be resurfaced some time in the near future).
- Sand filter with 1 horsepower pump runs about 8 hours per day
- Very windy area with a lot of organic matter. I check the baskets 2x per day and skim the pool 2x per day removing a lot of leaves and debris.
- Current Pool Temp is approx. 84 degrees.

Here are the issues:

I had some algae problems early on but we seem to have the algae under control. With repeated shocking and some algecides. The pool water is clear, but there is a fair amount of dirt on the bottom of the pool and it seems kind of milky and murky at the bottom.

I am now using liquid bleach from Walmart along with some pool shock that I purchased at Costco. (Trying to work through that). I do the shocking / adding of chlorine at night. Usually bringing the chlorine levels way up.

By the next evening the chlorine is down to almost zero again. I thought maybe I had little or no CYA in my pool so I ordered the test kit from here. Got it tonight here is what it told me.

FC - 3 PPM (max)
CC - 0
TC - 3 PPM
PH - 7.2
T/A - 110
CH - 400+
CYA - 100 ++

I don't know the last time the pool was drained. I am told the filter got new sand last summer. I am trying to stay on top of maintenance, but the amount of Chlorine I am burning through seems ludicrous. Any ideas / suggestions as to where I may be going wrong?

Thank you in advance for your guidance...
 
Use the FAS/DPD chlorine test from the kit so you can test higher chlorine levels. Put enough chlorine in the pool tonight after the Sun goes down to bring it to a level you can record.....say about 20ppm. Test the Cl about two hours after you put it in (give it enough time to circulate).

Next, test again for chlorine tomorrow AM. If you have a chlorine drop of more than 1ppm overnight, you have organics (probably algae) in your pool. Two things reduce chlorine....the Sun and organics in your water. By putting the chlorine in at night, you have eliminated the Sun.

Your high CYA is gonna' be another issue but I believe you should first test for chlorine loss at night....I think you'll discover you have algae.

(Measure and test and record carefully....the kit takes a little to get used to)

As an aside, I would recommend you not put anything else in your pool but chlorine for now. Powdered "shock" and algaecides will confuse the issue and skew your test results.
 
mauidad, welcome to the forum. You are in the right place (not to mention living in the "right" place 8) ) Dave's advice above is right on. Especially using the Fast/DPD powder for testing your chlorine. With your CYA level being above 100 ppm, you will need to keep your Free Chlorine (FC) at higher levels (see This Link for Chem Geeks new chart) and the OTO tests (re agent that turns yellow) just will not measure chlorine above 5ppm AND only measure Total Chlorine (TC). One other observation, from talking back and forth with another fellow Hawaiian a year or so ago on another forum, I recall his chlorine consumption was slightly higher than we "mainlander" experience. This will be compounded by the wind and lots of organic matter. Don't worry, once you make it through the next couple of weeks (be patient), you'll have a much better grasp on things and should have a routine that allows you to "stay ahead". Also, as Dave said, don't add anything at this point in time except bleach or liquid shock (12.5% Sodium Hypochlorite). Anything else will raise your CYA or CH even further and Algaecides will just increase your chlorine consumption. Your next step will be a series of partial water drains and refills to lower your CYA to a manageable and measurable number. One step at a time for now, get the FC to hold overnight.

Dave

P.S.- My pool in middle Tennessee is Perfectly Balanced and Crystal Clear if you want to trade living locations for a while...........
 
Your very high CYA level is going to make fighting algae difficult. You are going to need to get that down by replacing water. Fighting algae with that CYA level is going to require tremendous amounts of chlorine and cause other difficulties in the long run. One of the problems with the CYA test is that anything above 100 is going to test as 100, so your level could be quite high.
 
Thank you Dave's and Jason. Maui living isn't so bad. I will test again this AM and raise the chlorine levels with bleach tonight. A few questions:

1. If it is algae I am fighting, how will I do it with the extremely high CYA levels?
2. Is there a chart on the site here to give me an idea how much bleach to add to the 25k gallons to raise chlorine levels to a specific amt?
3. At what point should I keep my kids out of the pool?

Cheers,

Billy
 
One more thing...I think I have been cutting off my nose to spite my face with the shock...It is Aqua Chem Shock Plus 4 in 1. (Sodium dichloro-s-triazinetrione - 58.2%) Something tells me the excessive use of that is what has my CYA up so high...

I think I'll see if Costco will take the last box I have back and just load up on the bleach.

I suspect my pool hasn't been drained in years, is this something I should be considering or should I just isolate this Chlorine burn / CYA issue first...
 
You are absolutely right, your shock is adding CYA.

I would consider draining the pool, or at least some/most of it, to get the CYA down to an acceptable range.
You don't have to do all of it. Why waste the CYA you already have - right?

One of the calculators will tell you how much you need to drain/refill to get it down.

I keep some dichlor shock and trichlor pucks around because we have enough evap and splash out, that occasionally I use it to increase my CYA back to a good range. I use the pucks if I'm going to be away for a week or so.
 
1. If it is algae I am fighting, how will I do it with the extremely high CYA levels?
2. Is there a chart on the site here to give me an idea how much bleach to add to the 25k gallons to raise chlorine levels to a specific amt?
3. At what point should I keep my kids out of the pool?
Click to expand...

1A. You can still do it but your chlorine levels will need to be really high (see 2A) Getting your CYA below 70 or so would be very helpful.

2A. Yes, Jason has an excellent pool calculator in any of his posts. You'll find it very useful from here on out.

3A. That up for some debate. I have swum in muddy creeks and gotten leeches so take my advice for what's it's worth. That said, I think it's perfectly fine to swim in high levels of chlorine. I'm not sure if anyone knows a "magic" point where it is inadvisable but I have been in 20+ppm more than once and, so far, I feel pretty good.

The third eye I have grown actually makes it much easier to read the paper!! The neighborhood kids stare a little but I was never that handsome to begin with. (the first part, down to the "feel pretty good" is all true).

You'll get other opinions more cautious than mine.
 
Lets imagine that your CYA level is 150, it might be higher or lower but we need to start someplace. Normal day to day operation you want to keep FC at at least 12. To shock the pool you need to bring FC up into the 30s, say 35, and hold it there (test and add chlorine to bring the level back to where you want it at least three times a day). Keep in mind that FC around 12 will make the PH test read a little higher than it actually is and FC around 30-40 will make the PH test be totally wrong. So get the PH to around 7.2-7.4, chlorine is more effective at lower PH, before you start raising the FC level.

You can get a better idea of what your CYA level is by diluting some pool water one to one with tap water and then doing the CYA test with that and multiply the result by two. The results will be significantly less acurate but it will tell you if you have something near 100 or more like 200+. If you get a better CYA reading than my guess of 150 you can put that into my Pool Calculator, see the link in my signature, and it will suggest FC levels for normal operation and shocking.
 
Thanks Jason. I tested and retested CYA. It looks like it was about 150, maybe more. FC was going down to .5 or so overnight. So I think the organic assessment was dead on. I drained about 20% out of the pool and refilled. Looks like I got CYA down to about 100. I am trying to shock over the next few days...We'll see if we can lick the algae problem. We may be experiencing some wind and heavy rain over the next few days (the remnants of Hurricane Flossie). We'll see what happens with that.
 

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Should I fire the pool guy?

Huge Mahalo to those on the forum that helped me clear things up with the pool.

I have been using plain old Wal-Mart bleach and been shocking, brushing, and testing the pool religiously for about 10 days. I am happy to report that last night was the first night that I didn't have a massive chlorine drop. I think that I have finally may have the algae problem under control. I've been draining the pool a bit and refilling to lower my CYA levels. They are still unacceptably high (about 100) but the water is crystal clear. I also raised my PH a bit from 7.2 to 7.5.

Now that the pool water looks great, I have to save some money so that I can replaster it and upgrade to a saline system...

Hopefully that will be next spring.

Now a quick question...

Should I fire the pool guy?

We inherited a pool guy who was coming 1x per week and "cleaning" and maintaining the pool. Since I had no clue as to how to maintain the pool I kept him on. I have found that with about 10 to 15 minutes a day of work the pool is looking better than ever. I was the one who got the algae problem under control and have been directing him....Yes, I have some things to learn about the filter and I am sure things that I have not encountered...but at $150 per month, I think I can do this myself with maybe a little help from my friends on the forum here. Any thoughts?
 
Aloha, and welcome to TFP! You did a great job clearing your pool. Fire your pool guy? Well, our pool came with the house, but we didn't get a pool guy, so can't say :wink: .

btw, our oldest daughter moved to Poipu Beach, Kauai in Feb and took our granddaughters with her :cry: They love HI.

Joyce
 
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