Name: Pool shock 56 - 12lb
Brand: Standard Chemicals
SKU: 590720
Price: 61.99 USD
Availability: InStock

12 lb bucket · 41% below shelf price

Pool shock 56 - 12lb

Pool-store chemistry without the pool-store markup. Our 56% calcium hypochlorite is produced and tested in-house several times a day, then packed as twelve sealed 1 lb bags in a handled 12 lb bucket. It is unstabilized, so it adds no cyanuric acid, and it dissolves fast, poured straight in or pre-mixed first. One bag shocks about 8,000 gallons. Open one, use one, and the rest stay sealed and dry. Suits vinyl, concrete and fiberglass pools. Delivered straight to your door.

Ships in 1–2 business days

DELIVERED STRAIGHT TO YOUR DOOR

Lower 48

Product Specifications:

Title

56% Calcium Hypochlorite: fast-acting, professional-grade pool shock

Unstabilized (Adds No CYA): won't build up cyanuric acid in your water

12 Sealed 1 lb Bags: open one, use one, keep the rest dry

One Bag per 8,000 Gallons: dose by bag count, no scoop or scale

Fast-Dissolving: pour the bag straight in, or pre-mix in a bucket of pool water first

Suits Most Pool Surfaces: vinyl, concrete and fiberglass, when pre-dissolved

Made in the USA: produced, tested and date-coded in-house

Convenient Bucket: sealed storage with an easy-carry handle

Not sure how many bags you need? One bag shocks about 8,000 gallons.

SHOCK CALCULATOR

What you're paying for

Cal-hypo. Not the building it sat in.

A pool store bag of shock carries a warehouse, a distributor, a storefront and a markup. Take all of that out and here is what's left: twelve sealed pounds of 56% cal-hypo and a bucket to keep them in.

What actually changes

Four fewer things to think about

Not features. The specific small annoyances that stop happening when your shock comes pre-measured and sealed.

no scoop, no scale

Every bag is exactly one pound, so dosing is counting, not weighing. The calculator gives you a bag count — no kitchen scale, no measuring cup, no powder down your leg.

no cloudy monday

Shock after a busy weekend or a storm, at dusk with the pump running, and the water gets the whole night to recover instead of losing its chlorine to the sun.

no stabilizer creep

Cal-hypo adds no cyanuric acid, so shocking every week doesn't quietly push your CYA up until the chlorine you're adding stops working.

no half-open bag

Shock hates damp air. Twelve sealed bags means you only ever open what you're about to use — the rest stays dry until next week.

Work out your dose

Why there's no middleman in the price

We're the manufacturer. The shock is produced on our line, tested several times a day, packed in-house and sent to your door. Every step we don't outsource is a margin nobody gets to add.

60m+

Pounds produced a year

20+

Years in pool chemistry

100%

Of the supply chain, in house

Scale is why the price works. There's no sale price here, this is simply what it costs.

Four steps, one evening

SHOCK AT NIGHT. TEST BY MORNING.

Test first. Bring pH into the 7.2–7.6 range before you shock. Chlorine works far better in balanced water.

Run the Pool Shock Calculator. Routine dose is about 1.21 lb per 10,000 gallons, rounded up to whole bags. So one bag per 8,000 gallons. Algae doubles it.

Pour the bags in around the edge at night with the pump running. If you prefer to pre-dissolve, add the shock to a bucket of pool water, never water to the shock.

Run the pump 8–12 hours so it circulates fully. Test again, and swim once free chlorine is back in range.

Never let cal-hypo touch trichlor or any other pool chemical, and never let water into an open bag. Both are fire risks.

Get the 12 lb bucket

What's in it

One active. Nothing to decode.

You shouldn't need a chemistry degree to buy pool shock. There's one active in this bucket, and the rest is listed on the safety sheet.

Calcium Hypochlorite

Cal-hypo · 56% · CAS 7778-54-3

Cal-hypo, to everyone who actually uses it. 56% calcium hypochlorite, fast-acting chlorine with no stabilizer, so it hits hard and doesn't leave stabilizer building up in your pool water, week after week.

And the rest, in plain terms

Calcium chloride, 1.5 to under 5%

Calcium hydroxide, 1.5 to under 5%

Calcium carbonate, 1.5 to under 5%

No cyanuric acid, unstabilized

Exact concentrations: trade secret (SDS)

Nothing in there that turns into stabilizer in your pool water.

Ours against the shelf, line by line

Same shock, same job. Here's every place the money and the quality actually split — including the ones printed on the back.

12 LB OF 56% POOL SHOCK		Typical Shelf Brand
Priced direct from our facility
Tested daily, 56% calcium hypochlorite
Sealed 1 lb bags, open one, use one
Date-coded at production
Delivered straight to your door
Producer and SDS clearly published

Title

The shock the pros use, without the Saturday errand.

Title

Professional-Grade Strength

Made in the USA

Fast-Acting Shock

Date-Coded at Production

Ships in 1–2 Business Days

Professional-Grade Strength

Made in the USA

Professional-Grade Strength

Made in the USA

Fast-Acting Shock

Date-Coded at Production

Ships in 1–2 Business Days

Professional-Grade Strength

Made in the USA

Full strength, or you don't pay for it twice

Fresh from the line

Shock sitting in a hot warehouse and then on a store shelf loses strength before you ever open it, and nobody refunds the difference. You paid for 56%. Ours ships sealed from the line that made it, guaranteed at full labeled strength when it reaches you. Damaged on arrival, we replace it free. No return required, nothing to ship back.

Straight from the manufacturer

Guaranteed full labeled strength

Date-coded at production

The questions worth asking about price

Including the one about 68% that most shops would rather you didn't ask.

Does shipping eat the saving?

Shipping is calculated at checkout by weight and destination. Put the bucket in your cart and check the delivered number against your local store before you commit.

What does one shock actually cost me?

$5.42 a bag, and the calculator rounds up to whole bags. A routine shock on 8,000 gallons is one bag; on 16,000 gallons it's two, or $10.84. Algae or a green pool doubles the dose. Test pH first so none of it is wasted.

Is 68% better value than 56%?

Per shock, yes. A routine shock on 10,000 gallons takes one bag of 68% or two bags of 56%, and both buckets cost $64.99. Choose 56% if you want finer control on smaller pools or lighter top-ups; choose 68% if you shock a larger pool and want fewer bags per treatment.

Will it raise my cyanuric acid?

No. Cal-hypo is unstabilized, so it adds no CYA. That matters for your budget: once CYA climbs past roughly 100 ppm chlorine stops working properly, and the fix is replacing water, not buying more chemicals.

Can I mix it with my tablets?

In the pool, yes. In the same feeder, floater, chlorinator or storage container, never— calcium. Calcium hypochlorite and trichlor in contact is a fire hazard.

Where do you ship?

Lower 48 only. No Alaska, Hawaii, territories, APO/FPO or P.O. boxes. Ships in 1–21 to 2 business days, then 2–42 to 4 days on UPS Ground.

Two products, one line

Shock handles fast recovery; tablets handle the steady week in between. Both are made in the same operation, tested to the same standard, and shipped from the same dock.