Chlorine Locked?

[reesie]

My husband and child wanted to swim over the weekend so we waited until 4:00 pm today to add the washing soda and BaquaShock. I tested before we added them.
fcl 3
tcl 5
ccl 2
alk 170
cya 30
ph 7.5


I tested again at 9:00 pm
fcl 1
tcl 1
ccl 0
alk 200
ph off the scale

Chem_geek and Waterbear said wait 24 hours and start adding chlorine, if it's 0 ccl, until it holds a fcl reading. Lower ph before adding chlorine or after? How much chlorine should I add at a time and how often? I have cal hypo and 3 inch tablets and bleach ( if the store doesn't run out again!).
Then clean filter thoroughly and change sand.
Again, thanks for the help! All of you guys are the best!

[reesie]

I tested 0 fcl and 0 tcl and 0 combined chlorine so now I'm going to start adding chlorine. Any advice as to how much to add at a time and how often?

[chem geek]

You'll want to add Cyanuric Acid to the water as well as chlorine or else sunlight will break down your chlorine too quickly. Your 3" tablets will add both chlorine and CYA, but will take too long to add either. The Cal-Hypo is fine if your Calcium Hardness (CH) isn't high and the bleach is also fine. So you'll need to get some pure CYA or perhaps could get some Dichlor which dissolves quickly and can be added to give you both chlorine and CYA (at least some) initially. Up to you -- whatever is easiest for you to get. Most people get pure CYA and put it in a sock or panty hose to hang over a return or in the skimmer for faster dissolving (some add it slowly to the skimmer to get caught in the filter, but that usually takes longer to dissolve).

If you have some CYA in the water, you can get your FC up to around 3 ppm to start with, not more than 5 ppm, but just note that it may drop quickly initially until you get more CYA in the water so you'll probably be adding chlorine multiple times per day the first day or two.

[reesie]

I have good news and bad news...I think. I don't have any combined chlorine so far. But I also don't seem to be having any luck at getting my free chlorine or total chlorine levels up.
My cya is 60
ph 7.6
alk 150
the most I've gotten the fcl to is 1, tcl was the same
I've added 16 ozs. cal hypo (65%) at a time
Tonight we added 24 ozs.
Should I go ahead and change the sand now or wait until I can get it to hold a fcl reading?

[waterbear]

Change the sand! There is probably a lot of gunk in their creating the chlorine demand.

[CarlD]

Normally we NEVER recommend changing sand, but after a bacquajunk usage or conversion you must.

After this stick with chlorine and you'll never have to change your sand again. I'm 9 years on the same sand. Watermom is 14 or 15 years on the same sand.

Carl

[Watermom]

Nah, I'm "only" on my 11th season with the same sand. It is Al who is on year 14 or 15.

[reesie]

We changed the sand 7/1/2011. No combined chlorine most of the time, but I still can't get a good free chlorine reading. I did have a combined chlorine once of .5 I'm averaging putting 12 - 24 ozs of 65% cal-hypo every night.
My readings tonight were
fcl 1.5
tcl 1.5
ccl 0
ph 8.0
alk 140
cya 60

I put 12 ozs. cal hypo and 20 ozs. dry acid to lower ph

Should I be using so much every day?
The water is great! No smell, beautifully clear!

[chem geek]

12 ounces of 65% Cal-Hypo in 15,000 gallons is 3.9 ppm FC so yes that is much higher than normal, especially since it's 12-24 so 4-8 ppm FC every day. See this thread where the most typical daily chlorine usage is around 2 ppm FC and usually ranges from 1.5 to 3 ppm for most residential pools.

As for the acid and high pH, that is because of your high TA level. The TA will drop over time and the pH will become more stable. You can add more acid to lower the pH to speed up this process, but right now I think we've got to figure out the high chlorine usage. Perhaps its persistent remnants from the Baquacil conversion. I'd track your usage over the next week or so to see if it slows down. Quite frankly, if we knew in advance how bad this conversion was going to be for you, then I would have suggested changing the water instead, as painful as that might have been.

Note that your Calcium Hardness (CH) level will increase over time since for every 10 ppm FC added by Cal-Hypo it also increases CH by at least 7 ppm.