“When the water turns, this turns it back.”
68% Cal-Hypo Shock
The reset button for your pool.
★★★★★ New · be the first in Houston to weigh in
How much, and how long it lasts
| Pool size | Per shock | Shocks in a 25 lb bucket |
|---|---|---|
| 10,000 gal | 1 lb | 25 shocks |
| 15,000 gal | 1.5 lb | ~16 shocks |
| 20,000 gal | 2 lb | ~12 shocks |
| 25,000 gal | 2.5 lb | 10 shocks |
| 30,000 gal | 3 lb | ~8 shocks |
Double the dose to clear algae. Shock in the evening with the pump running. This gets you close. Confirm with a test strip.
- 01
Pre-dissolve or broadcast
Broadcast over the water with the pump running, or pre-dissolve in a bucket first for plaster pools.
- 02
Dose for your pool
About 1 lb per 10,000 gallons for a routine reset. Double it to clear algae. Use the chart.
- 03
Run the pump
Shock in the evening and let the pump run overnight. Wait until chlorine drops back to normal before swimming.
- Active ingredient
- Calcium hypochlorite (cal-hypo)
- Concentration
- 68% available chlorine
- Form
- Fast-dissolving granular
- SKU
- PV-CAL-25
- Registration
- EPA-registered
Oxidizer. Keep dry, sealed, and away from other chemicals. Never mix with chlorine tabs. Read the full label before use.
“Cal-hypo is the fast counterweight to everyday chlorine: it dissolves quickly, adds no stabilizer, and clears a cloudy or green pool in a single dose. Twenty-five years in the business taught us which shock actually works. This one does.”
The Pool Health Club · Houston
What Houston says
★★★★★
Be the first in Houston to weigh in.
No reviews yet, and we won't invent any. Run a bucket for a season and tell us how your water looks. Verified notes from real Houston pools will land right here.
Can I use this with the chlorine tabs?
Yes, that is the idea. Tabs hold your chlorine steady day to day; shock resets the water when it needs it. Never mix the two products in the same container, though.
When should I shock?
After heavy use, a big rain, or a party, or any time the water looks cloudy or dull. A weekly shock during peak season keeps you ahead of trouble.
Does it add stabilizer (CYA)?
No. Cal-hypo adds no cyanuric acid, which is exactly why it pairs cleanly with stabilized tabs. It does nudge calcium up slightly over time.
Can it ship to me?
Free same-day delivery in Houston, and ground shipping across Texas. Like all pool sanitizers, it ships ground only and never in the same box as the tabs.
