Need Help with Chlorine Levels

I have been to my local pool store (3) times now to get my pool water tested since I did not trust my readings. The pool water has been very clear since the inital opening on May 26. During my first visit many things were off to include CYA: 0, Totl Chlorine: 3.6 and Free Chlorine 0. The company gave me a bunch of chemicals to regulate all sorts of different items in the pool to include 16 lbs of Chlorine.

Second visit to the pool company resulted in CYA: 26, Tot. Chlorine: 1.9 and Free Cholrine 0. At this visit they send me home with 12 more pounds of Chlorine shock to bring the levels up and told me to lower my ph to help the clorine out.

Third visit today resulted in CYA: 0, Total Chlorine: 0.3 and Free Chlorine 0. They told me that they are going to run a different test now to see how much chlorine my pool is using before telling me what to put in next. However they said it would probably take at least another 20 lbs of Chlorine.

This is getting real old and expensive very fast. Does anyone have any advise. Todays readings are:

Temp: 70
CYA: 0
Tot Chlorine: 0.3
Free Chlorine: 0
PH 7.2
Total Alkalinity: 100
Hardness: 300

18 x 37 Grecian Shaped Vinyl pool
21,500 Gallons
The pool water is crystal clear

First of all, welcome to the forum. Secondly, you need to read, read, read here on the forum and also on the sister site www.poolsolutions.com and you will learn a lot about taking care of your pool easily and inexpensively.

It sounds like, as we like to call it around here, that you are getting "pool-stored" which means that the pool store is selling you a bunch of stuff you probably don't need and emptying your wallet.

You need to quit relying on the pool store to test your water. Buy yourself a good dropsbased kit and test it yourself. It is not difficult and your readings will be more trustworthy in most cases. Since all you have for now are readings from the poolstore, we'll have to go with those.

Your alk is fine. A calcium hardness reading of 300 is OK, but don't add any. Vinyl pools don't need it. By any chance, did the pool store advise you to add any? Your ph is OK at 7.2, but you never want to let it drop below 7.0. Readings below that are acidic and can damage your pool. If it does drop, you can use some 20 Mule Team Borax (in the laundry aisle at Walmart) to raise it.

What have you been using as your source of chlorine? Don't just tell us 'shock.' We need to know ingredients. Post with that info and somebody here can advise you how to proceed with chlorinating your pool.

The pool company did in fact have me add Calcium Chloride Flake to raise the Calcium Hardness when the initial results were 95. I told them that I had read (on this forum) that Vinyl pools didn't need Calcuim, but they told me that I still need to maintain a certain level to prevent damage in my pool lines and my pool pump parts.

When I was refering to shock, the product is Chlorinated Granules. The main ingredient is Calcium Hypochlorite (47%). The labels dont break the other items down.

That's why your calcium is so high--the calcium flakes (which you didn't need) raised it, and then all the cal-hypo (shock) they're having you put in the pool raised it a bit more. At this point, don't let it get any higher, or you may be looking at a milky pool. (Drain and refill is the only way to lower it.) That also explains why your CYA isn't rising. CYA only rises if you put it into the pool, so the fact that your pool store "saw" some CYA once and didn't "see" it again later is an indication of faulty testing--which is why Watermom advised you to get your own drop-based kit and do it yourself. It's definitely the best investment you'll make in your pool, and will have already paid for itself with what you've spent at the pool store!

You're not going to be able to keep chlorine in the pool until you have some stabilizer (CYA) in it, and if the water is clear then you're wasting your money shocking it to try to keep a residual. Go to WalMart, Home Depot, or Lowe's and buy a container of CYA (also labeled balancer, conditioner, or stabilizer, but the main ingredient is isocyanuric, or cyanuric, acid--it's the same stuff). Follow label instructions for the amount to raise your CYA to around 20-30 ppm, but don't broadcast it like the label says--either put it slowly into your skimmer and don't backwash it for at least a week, or put it into a sock or old panty hose and put it in the skimmer or tie it in front of a return to let it start dissolving. In the meantime, while you're at WalMart, buy several jugs of the generic, ultra bleach, and use that to maintain your chlorine level by adding it at night after the sun is off the pool, so it has plenty of time to sanitize your pool before the sun hits it in the morning. At the end of the day you'll have zero chlorine residual due to the sun, but once the CYA starts to dissolve you'll start to see some residual.

Do yourself a favor and save yourself some money--save the pool store for buying toys!!

Janet

Good advice from Jan. One other thing I might add is that for the first week or so until your cya dissolves, you might want to test and add bleach morning and evening. After that, you should be able to just test and dose it with bleach in the evenings only.

Sounds great. I got the Bleach (6%) and supplies as you told me. How much bleach do you put it. I looked at the bleach calculator and another chemical calculator that is listed on the site but it only has me adding approximately 134 oz of 6% bleach. to raise teh FC to 3 PPM. That dosent seem like very much bleach to me. Could you advise if that sounds correct or not?

Quote:

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Originally Posted by stateroaddog

Sounds great. I got the Bleach (6%) and supplies as you told me. How much bleach do you put it. I looked at the bleach calculator and another chemical calculator that is listed on the site but it only has me adding approximately 134 oz of 6% bleach. to raise teh FC to 3 PPM. That dosent seem like very much bleach to me. Could you advise if that sounds correct or not?

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Actually, it's spot-on. You have 21,500 gallons. 1 gallon (128 oz) of 6% will raise 20,000 gallons 3ppm.

Here's the rule of thumb:

One gallon of bleach (whatever its strength is) will raise 10,000 gallons by that strength--In other words: If you add 1 gallon of 5.25% to 10,000 gallons it raises it 5.25ppm. 1 gallon of 6% raises it 6ppm. etc. So....if you add 1 gallon of 6% to 20,000 it's diluted to half-strength--3ppm. You are just over 20,000 gallons at 21,500 gallons. So....you are just over 1 gallon by 1/2 cup.

See how it works? The Rule of Thumb uses the same formula as the Bleach Calculator, but only at the simplest values: 1 gallon. 10,000 gallons. So you adjust up or down from that.

Thanks. That makes me understand it much better..