Chlorine Locked?

[reesie]

We used Baquacil for 15 years. The first 12 were great but the last 3 were nightmares. Last year we barely swam at all. We spent a fortune on chemicals last year and finally gave up in late July and on the advice of the pool store, let all levels of Baquacil go to 0. We closed the pool with no chemicals added. They advised to start fresh with massive does of chlorine at the start of this season. The pool was green when we closed it.
It was green when we opened it as expected. Our pool is 18x33 above ground, 15,000 gallons. We put approx. 12 gallons 6% bleach in it over a week when we opened it. It turned a flourescent green and then after shocking and putting 3 inch tablets in a dispenser got a milky color. We took a water sample in. Ph and alkalinity were high. Chlorine was non existent. They said to lower ph and shock it. They said there was no Baquacil in it. We shocked it again. (3 lbs). We took another sample. Ph was 7 alk was 160 hardness was 80 free cl 0 tot cl 1.8 stab 20. They said put 1lb. ph up, wait 1 hour and put 3 lbs. stabilizer, then tomorrow put 21 lbs. calcium hardness increaser in 2 doses , wait six hours and then put 3 lbs. shock after 8:30 pm. We did all this and also had 3 3 inch tablets in dispenser and took another sample 4 days later. Results: alk-160 ph-7.2 cya-30 tot hard-80 tot cl-1.7 fr cl-0. The pool store said to let alk come down by itself. They said to shock with 3lbs shock that night. They also said to crush a chlorine tablet and put in skimmer and bring another sample the next day. They also said to put 21 lbs. calcium hardness increaser. We did.
We brought another sample yesterday. Results: alk-160 ph-6.8 cya-30 tot hard-90 tot cl-7.8 fr cl-0
They said put 1 lb. ph up. Wait 1 hour, put 3 lbs. NON Chlorine Shock, crush another 3 in. tablet and put in skimmer. Don't put any more calcium hardness increaser right now. Bring another sample Monday or Tuesday.
Help! Why can't I get any free chlorine reading? I'm wondering if I can trust the advice I'm getting. I was told to put ph down in to lower my alk (160) when my ph was 6.8 which is already low for ph. I'm confused.

[Watermom]

To make it easier, I'm going to post all your numbers in a list:
TA (alk) 160
pH 6.8
CYA 30
CH (calcium hardness) 90
TC 7.8
FC 0

Enough with the pool store having you throw everything but the kitchen sink in your pool. It would help you a lot to read some of the threads in the Baquacil section of the forum. Many people have written about their conversions there. The basic of it is that you keep testing and adding bleach as many times a day as you can and each time you add bleach, take it back up to shock level. For a pool with a CYA of 30, that would mean up to 15ppm. Try and sustain this reading. You have already found that your pool will turn all kinds of shades of green; that is to be expected, but keep hitting it with bleach. Also run your pump 24/7 and backwash as needed when the filter pressure rises. When you get to the point where your water clears up and you can go from sundown one evening til sunup the next morning without losing more than 1ppm of chlorine, you'll be almost there. For reference, in a 15K pool, each quart of 6% bleach will add 1ppm of cl. That will help you to determine how much chlorine to add each time you test.

You're going to need a good kit. Take a look a the Amazon link in my signature below. We recommend the Taylor K-2006 or 2006C which is the same kit with larger quantities of some of the most used reagents. Well worth the money and it will make your maintenance easier. Until that time, you can use the dilution method to measure higher numbers than your current kit will most likely read. More info about that here:

http://www.poolsolutions.com/gd/how-...d-testkit.html

Most critical right now is your pH level. You need to get it above 7.0 ASAP as any reading below that is acidic and can damage your pool. Add some 20 Mule Team Borax (laundry aisle at Walmart) slowly to your skimmer while the pump is running, breaking up any clumps. Test pH a few hours later and add more until you get the pH between 7.2-7.8. I'd start with a box at a time. After your pH starts to move, you might want smaller additions. By the way, high chlorine levels will give false pH readings, so get this pH adjusted before you start shocking the pool with bleach.

Don't worry about anything else right now. Don't use any more pucks, non-chlorine shock, calcium hardness increaser, etc. (In fact you don't ever need calcium hardness increaser ever again. Vinyl pools don't need it.) Only need lots of bleach and some Borax.

If you follow these steps, you're pool will clear up. After your conversion is complete, you'll want to change your sand, but not until then. Keep us posted how things are going. And welcome to the forum. Thanks for becoming a subscriber. We appreciate it!

[reesie]

Thank you for your reply. I ordered the test kit.
We thought the conversion process was complete when the pool cleared up. It is crystal clear but has had a free chlorine reading of 0 consistently. We already changed the sand (at the pool store's recommendation)at the end of last season and again last week. I had read the Baquacil conversion posts here but thought when the pool cleared up we were through with the conversion.
We will take another sample tomorrow since I can't get a decent reading with the strips I have and then try to raise the ph. I believe the ph is between 7.0 and 7.2 if I can believe my strips. We just put ph up in Saturday night after the pool store test.

[Watermom]

How much bleach are you putting in at a time? How often are you adding it? Keep an eye on that pH. Don't let it drop below 7.0.

[aylad]

You're not quite finished until uou can go from sundown to sunup without losing more than 1 ppm chlorine. Even though the ppool is clear you may still have a little more time left before you achieve that step....

Janet

[reesie]

Okay, I received the Taylor kit 2 days ago. I tested last night at 9:00pm
fcl 6
tcl 25
ccl 19
alk 160
ch 250
ph 7.8
cya 50
I tested again this morning at 6:00 am:
fcl 6
tcl 19
ccl 19
I didn't lose any from sundown to sunup but I lost a lot from 5:00 pm til 9:00 pm. I put 4 gallons bleach in at 5:00 pm.
Now what do I need to do to lower the fcl & tcl and get rid of the ccl? Do I need to lower the ph to below 7.6? Is that the next step? Would I go back to putting a non chlorine shock in?

[CarlD]

For the moment, don't worry about pH. Yeah, it's high, but that may be due to the TC being so high and it's falsely elevating the reading.

Do not, not, NOT add anything but bleach/Liquid Chlorine at this point unless Ben, and ONLY Ben, AKA PoolDoc says to do so!


In my opinion, you need to raise your FC to 15, minimum, and keep it there. Given that your CYA is 50, at the top end of the 30-50 scale, you could even take FC to 20ppm safely.

You still have stuff you have to get rid of in your water even if the Bacquagoop reading is zero. It's still all over your system, and you have to get rid of it.
That is why, I think, you have such high CC levels. You should see, after a few days, the CC reading come down. When it's zero and stays there, you are finally done with your conversion.

At that time, you'll have to clean out your filter. If it's a sand filter you'll need to replace the sand, absolutely. If it's DE, you'll have to clean the grids, maybe even soak them in Muriatic Acid (I'm not the DE or cartridge whiz). If it's a cart, I don't know if you can clean the element or have to replace it, but if you can I expect at a minimum you'll have to soak it for a day or two in electric dishwasher detergent. Any cart users out there that have done the Baq to Chlorine conversion?

Carl

[PoolDoc]

These two threads:

http://www.poolforum.com/pf2/showthr...hlorine-Locked
http://www.poolforum.com/pf2/showthr...il-to-chlorine

seem to be both products of an issue I don't remember dealing with before: pools with a LONG history of Baquacil use, before conversion.

I talked with "Aciam" at length last night, and agreed upon the following:

#1 - Test with OTO ; ignore FC / CC differientiation
#2 - Dose to dark yellow (~10ppm); allow it to drop to medium yellow (~2 ppm)
#3 - Continue filtering 24/7
(Aciam's water is clear, but some sort of surface debris is forming continuously and being collected on her skimmer sox)
#4 - Dose with polyquat that the FIRST signs of algae (slippery sides on Aciam's vinyl AG pool)
#5 - If no resolution after a few days, consider drain and refill (AG pools ONLY!)

My **guess** is that there's a huge accumulation of Baqua-goo from the years of Baquacil use, and that -- whatever else Baqua-goo is, chemically speaking -- it is very resistant to chlorine oxidation. The high CC levels are a result of slow (but sure) oxidation by chlorine.

What's weird is that her FAS-DPD readings did NOT match her OTO test results at all. I trust OTO more than DPD, so I made the recommendation above. However, I had to tell her I really have no idea how cleanup will take. I've emailed Chem_Geek to see if he's collected any info on this.

Ben

PS: It sounds like "reesie" is in the same situation. Ben

[reesie]

I tested again when I got off work:
fcl 2.5
tcl 25
ccl 22.5
alk 160
ph 7.6
cya 50
I added 4 gallons bleach at 8:30 pm. Will test again in 1 hour.
I didn't quite understand Pooldoc's instructions. I'm new to all this chlorine stuff. Do I need to go get another different kind of test kit for #1?
Could you explain #2 more? Is that part of the OTO test kit colors?
I understand 3. My water is crystal clear, also. No algae. My 9 year old is also upset she can't swim. She was swimming when we first opened it, before we started adding all the large amounts of bleach.
I also understand 4 & 5.
I hope it deosn't come to #5. I live in a small town with a municipal water system and they absolutely forbid filling swimming pools.
Thank you all for your help.

[CarlD]

The simplest kind of drop testing is the kit that has a plastic cell marked for chlorine/bromine on the left with a yellow background and pH on the right, with a red background. It's sold in pool stores and K-Mart, WalMart and other places. It can run $5-$15 depending on the brand and features. WalMart used to have a GREAT one by HTH that also did total alk, hardness, and CYA testing, that ran about $12-$15. But the typical inexpensive kit is fine as long as it says OTO or OTO/pH
The chlorine test (forget about the bromine--that's for bromine pools) is called OTO. You fill to the line, add 4 or 5 drops (depending the brand) and compare the color of the water to the yellow background to read the total chlorine level.
pH on the other side is just the same.

What Ben is saying is that he doesn't trust the reading you are getting (not that it's your fault or you are doing anything wrong) but that he wants you to test the water with the OTO test instead. The dark yellow color he's talking about is much darker than the range of the background on the test tube (called a test CELL). That water color should be dark yellow. After yellow, as the chlorine gets more concentrated, it goes orange then brown.
It's not very precise, but it's very simple and very rigorous, in other words it pretty much always works.

So...if the water is NOT dark yellow in the OTO cell, add bleach to the pool until it comes out that way. If it IS dark yellow (as I said, much yellower than the cell's background) it's already where Ben wants it. Then just let time pass and don't add any bleach, letting the color go to medium yellow (this all may take a day or two).

What I don't know is how much Polyquat Ben wants you to use. Usually 1-2 ounces is enough--if your pool is clear. But what is clear is to do it if the pool sides feel slippery.

I THINK, but don't know, that if the water "behaves" it will be safe to swim.

I hope this helps clear up Ben's instructions.

Carl