New IG vinyl liner - initial results

I have a 16X40 IG pool, about 25,000 gallons. The liner went in Tuesday night and it took nearly two days to fill it. (This is in metro Atlanta. It'll be near 90 today, but my pool's in the shade).

I shocked the pool with 15 quarts of bleach.

To adjust the initial ph and alkalinity, I added borax and baking soda. I'm still adjusting. I added a tri-c puck for stabilizer.

My numbers this morning:

ph - 7.5
alk - 40
fc - 6 ppm
cc - 0
tc - 6 ppm
cya - (before the addition of a 3-inch puck)

Questions:

1) How much stabilizer will I get out of a 3-inch puck?

2) How much more baking soda should I add to increase the alk - and about what should my target alk be: 100 ppm? Last year my alk was about 150 and ph stayed at about 7.5

3) Am I past the shocking stage? That is, once I've established enough stabilizer to maintain my bleach, can I just add enough bleach to keep my FC sufficient or do I need to shock for longer?


Thanks,

Z

New water: FC and TC = 6ppm, no CYA yet...
No need to shock. You should have gotten FC of 7.8ppm, but it must have metabolized something--and no CC measured. That's good.

I don't quite know how to compute the amount of CYA 1 puck will add to a pool. What I would do is use pucks (if you must) in a floater and measure CYA weekly, at a minimum. When it passes 30ppm, stop.

Or you can buy CYA directly. Figure, from the package, how much you need to reach your target in your pool, then use 1/4 to 1/2 what you computed. Add it and wait a week to test CYA. (use the rules on putting it in a sock, or in the skimmer and not backwashing--search the forum).

Alk: I like to add 1lb via the skimmer, wait a day, test, and add another pound, and keep it up until TA passes 100. 150 is FINE in a vinyl pool--I like 180 to be my max before I take action to lower it ...Concrete pool owners--your max is 125.

But overall, I think your pool is looking terrific and you are doing everything right to start off with healthy water! Well Done!

Carl D:

The pool came with chlorinator/feeder that takes pucks. The previous owner had a leftover supply of pucks, so I'll use that to get my CYA - unless it makes more sense to just buy it and use it straight.

Thanks for the advice. It's great that everyone is so willing to share their knowledge.

The pool came with the house we bought last year. It's the first time I've ever maintained a pool.

Most of my knowledge has come from the discussions on this site. I relied on a pool service for about six weeks last year, just to understand how my system worked. I supplemented that by reading here.

Again, thanks for looking at my numbers.

Carl's got you on the right track, and my kudos too, for doing your homework. The only piece of advice I'd add would be to add a small amount of straight stabilizer (maybe enough of a dose for 10-20 ppm?) as kind of a "loading dose", then let your pucks bring it up to where you want it. The problem is that it will take several weeks before the pucks are able to put enough CYA in the water to actually hold a chlorine residual.

Janet

I didn't realize you had an in-line chlorinator. Use that instead, of course, but watch your CYA.

I have an in-line feeder too, and I only use it when I am going to be away. I like to start my pool off with a cya of 30, so that when I use the pucks I don't worry about the cya getting too high. It is nice to have as a back-up, but otherwise I use bleach. I also use cal-hypo shock to bring up my calcium, which I keep at about 125 in my fiberglass pool.

In fact, I'm heading out this weekend, so I've dropped a couple of pucks into the feeder to keep things going while I'm away. Hopefully, things will not have gotten too far out of hand by the time I get back.

This morning:

ph - 7.5 (started at 7.2, but trying to maintain 7.5)
alk - 80 (trying to adjust to about 100)
fc - 6 ppm
cc - 0
tc - 0
cya - 0 (but trying to adjust to 25-30)
h20 temp - 70 degrees (pool is 3/4 in the shade)


Happy Memorial Day weekend!