Chlorine Locked?

[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.

[CarlD]

It's been so long my memory's starting to go!

[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.

[reesie]

The readings have been good.
7/10/2011
fcl 2
tcl 2
ccl 0
ph 7.6
alk 140
ch 130
cya 60
I put 48 ozs. dry acid in and 9 ozs. cal hypo.
We now believe we have a leak but we're holding the chlorine and we don't have combined chlorine!!! We're losing more water than we should be losing to evaporation. We've spent the last week going over every inch of the liner trying to find a leak. We haven't been able to find it, but have found an area that the sand underneath has shifted, so we have an area to look at harder.
I haven't put anything else in until tonight because we are letting the water level drop to see how low it will go to see if the hole is in the bottom or on the walls. We had to cut the pump off when it dropped below the skimmer. I checked the water tonight.
fcl 1.0
tcl 1.0
ph 7.4
alk 125
cya 60
ch 130

[Watermom]

Reesie,
I moved your question to the Construction and Repair section of the forum since this issue has nothing to do with the Baquacil forum. You can find your new thread here:

http://www.poolforum.com/pf2/showthr...-a-vinyl-liner

[reesie]

I no longer have combined chlorine. The chlorine demand has settled down. I've only been using 1.5-2 ppm a day for the last 10 days. I'm still battling high ph, though.
fcl 4
tcl 4
ccl 0
alk 125
ch 140
ph 7.4
cya 50

I just had to put 42 ozs. dry acid in to bring the ph down to 7.4
I'm having to put around 40 ozs. dry acid in every week to lower ph. Is this normal? I don't remember ever having to adjust the ph so often.

[waterbear]

Drop your TA down to about 80 ppm and your pH will not be rising as fast. Also, muriatic acid is cheaper and more effectie than dry acid.

[reesie]

Okay, thanks, we'll try that.