475 gallons, how much powder "Ultra Shock" to use??????

[PoolDoc]

OK. Treatment for a 500 gallon mini-pool.

1. Get a cheap OTO/phenol red test kit at Walmart.
2. Buy 2 gallons of PLAIN 6% GV bleach.
3. Buy a 4.75 lb box of borax
4. Buy a container of spa acid, or get it from Amazon.
5. Buy anything you can't find, plus the other items, from Amazon.

Then do this:

Start-up treatment
1. Drain and refill your pool.
2. Add 1/2 cup of bleach; add 1 cup of borax; add 1/2 cup of dry acid.
3. Mix completely and test.
=> If chlorine is not > 3 ppm, add a 2nd cup of bleach
=> If pH is greater than 7.8, add 1/8 cup of acid
=> If pH is less than 7.2, add 1/4 cup of borax
=> Wait 1/2 hr and retest. Add again, as needed.
4. Once everything is adjusted, move to daily treatment.

Daily treatment:
1. Test pH and chlorine each AM, and add 1 teaspoon of polyquat.
=> If pH is greater than 7.8, add 1 tablespoon of dry of acid; if pH is less than 7.2, add 1/8 cup of borax
=> If chlorine is less than 1.0, increase your PM dose by 1/8 cup of bleach; if chlorine is greater than 5 pm decrease your PM dose by 1/8 cup
2. Add 1/2 cup (plus/minus adjustments) bleach EACH evening, within an hour or so of sunset.
3. Add 1/4 cup of bleach after EACH swim period.
4. Drain and refill every 2 weeks, if you are swimming regularly.

Walmart items:

HTH 6-Way Test Kit if available; otherwise whatever OTO / phenol red kit they have.
PLAIN 6% household bleach (Walmart Great Value bleach) => big box store brands are preferable,
since they are (a) usually 6%, & (b) not mixed with goop, like some Clorox blends.
20 Mule Team Borax
granular spa or small pool acid?
plastic measuring spoons and cups -- use SEPARATE measuring containers for acid and chlorine.

Amazon items:

Polyquat info & purchase link
Kem-Tek Dichlor 2.5lbs
Leisure Time 22338 Spa Down, 2-1/2-Pound

Read the Intex recipe, in this section. If you buy some dichlor, we'll help you with doses. Dichlor would be easier than bleach, but you'll have to buy from Amazon to be sure of getting un-gooped-up dichlor.