Help with appropriate shock for vinyl in-ground

[CarlD]

The great thing about the B-B-B method is at its simplest, it's very, very easy.
The one KEY thing is you need to be able to test properly, which is why we recommend the Taylor K-2006 or an equivalent FAS-DPD test kit (Leslies has one, so does another pool forum).
You should also have a simple OTO/pH kit, preferably one that measures chlorine to 5ppm. The Taylor K-1000 is the best and costs about $10.

You test with the OTO every day and adjust your chlorine and pH as needed (I haven't had to adjust pH in 6 weeks).

Once a week you test Free Chlorine (FC), Combined Chloramines (CC), pH, Total Alkalinity (TA), and Stabilizer/Cyanuric Acid (CYA).

If you have a concrete/shotkrete/gunite/plaster/tile pool, you test Calcium Hardness (CH) as well.
But if you have a vinyl pool you only have to test it twice a season (unless you use lots of Cal-Hypo).
And, if you have a Salt Water Chlorine Generator you need to test for salt,too.

Your ideal daily level of Chlorine is determined by your weekly test of stabilizer, as well as the Best Guess Chlorine Chart (See Ben's and Watermom's sig for the link). So...my CYA level is 30ppm. Therefore my daily chlorine level should be between 3 and 6 ppm. As long as it stays in that range, or doesn't fall to far below it for long, I don't have to shock. It works out that I have had to add about 1 gallon of 6% bleach every other day for almost 20,000 gallons. Simple.

pH? As I said I haven't had to adjust it in over 6 weeks---but that's because I check it and watch it. If it gets low, I can add Borax (which adds borates and can inhibit algae), or I can aerate, which adds nothing, but raises pH. If it's high I can add Muriatic Acid or Dry Acid (the generic for Low'n'Slow)

Once a week I "worry" about mainly T/A and CYA. Since my pH has been stable at 7.6, I haven't done ANYTHING to change my unusually low T/A of 60ppm. T/A's JOB is to buffer and stabilize pH. My pH is stable, I don't mess with it.
Since I've had to add the bleach (Actually, I use Liquid Chlorine and 1/2 gallon of that is the same as one gallon of bleach) at the rate of 1 gallon every other day, I'm planning to raise CYA to 50 or 60 and maintain chlorine at the 5 to 10ppm level.

I have a vinyl pool, I never add Cal-Hypo, so, I measure my Calcium Hardness twice a season. It was at 60ppm early on and I'll probably measure it at the beginning of August, just to be sure.

If you stick with bleach, Borax, Baking soda, Muriatic Acid/Dry Acid and 100% Cyanuric acid, you don't need anything else in your pool but kids and fun.

It's very possible to work with Tri-Chlor tabs, Di-Chlor powder, Cal-Hypo, chlorinators, etc. and STILL follow the B-B-B method. You just have to know what each product does and keep an eagle eye on your daily and weekly tests. So...if I'm using Tri-Chlor tabs, I'm seeking to do 3 things: Keep a constant flow of chlorine, lower my pH, and raise my CYA level. I could do each separately, but sometimes this is more convenient.

2 caveats.
Do NOT use ANY algaecide but 60% polyquat (60% Poly....<something>... and no other active ingredients). Other algaecides do more harm than good.
HTH products are now "cocktails" of things you may not want, like "double acting tablets" that contain tri-chlor AND copper, which stains fittings and turns blonde hair green. Always check the label. The Namco chain in my area is no longer selling 100% CYA--they mix it with Soda Ash (which is far cheaper but don't tell you how much). Soda Ash raises both pH and Total Alk.

Carl