BioGuard Burnout 73 1 lb. | Pool Superchlorinator

• 1 x BioGuard Burnout 73, 1 lb bag
• Full manufacturer label with application directions, timing, and safety information

One bag treats up to 16,500 gallons. A 20,000-gallon pool needs two bags for a full treatment, and a 30,000-gallon pool needs two. Calculate your total before ordering, particularly if you shock weekly through the summer.

73% Calcium Hypochlorite — The Highest in the BioGuard Line

The strongest concentration of any BioGuard shock, delivering maximum oxidizing capacity from a single one-pound bag.

One Bag Treats 16,500 Gallons

High coverage per bag means fewer packages to buy, carry, and store — and less handling of a hazardous material overall.

Adds No Cyanuric Acid

Calcium hypochlorite is unstabilized, so shocking with it doesn't drive stabilizer levels upward the way dichlor products do. On a tablet-fed pool, this is how you shock all season without eventually locking up your chlorine.

Destroys Organic Contaminants

Oxidizes the perspiration, body oils, sunscreen, cosmetics, and nitrogen compounds that bathers leave behind and that make water smell and irritate.

Restores Sparkle and Clarity

Clearing the organic load is what brings back the brightness in water that tests fine but looks dull.

Reduces Organic Contamination

Regular superchlorination keeps the organic load from accumulating to the point where it starts consuming your sanitizer faster than you can replace it.

Quick Dissolving

Broadcasts directly over the deep end with the pump running and goes into solution rapidly.

For Use With All Pool Surfaces

Suitable for plaster, gunite, vinyl liner, fiberglass, and painted finishes when applied correctly.

The active ingredient is calcium hypochlorite at 73%. On contact with water it dissociates and releases hypochlorous acid — the form of chlorine that does the actual sanitizing and oxidizing.

Hypochlorous acid works on two fronts at once. It destroys bacteria and other microorganisms by disrupting their cell structure, and it oxidizes the non-living organic load: perspiration, body oils, sunscreen, cosmetics, and the nitrogen compounds that bind to free chlorine and form chloramines. Chloramines are the source of the sharp "chlorine smell," the burning eyes, and the skin irritation people blame on too much chlorine. In reality they're evidence of too little effective sanitizer. Superchlorination drives free chlorine sharply upward for a short period, which breaks those bonds apart and resets the water.

Concentration is the whole argument for this product over a lower-percentage shock. At 73%, nearly three-quarters of the bag is working chemistry. A 57.8% product delivers meaningfully less oxidizing capacity from the same weight, which is why coverage per bag is so much higher here.

What makes cal hypo different from the other chlorine shocks is what it doesn't carry. Dichlor and trichlor are both built on a cyanurate backbone, so they release chlorine and cyanuric acid together. Calcium hypochlorite has no cyanurate at all — it releases chlorine and calcium. Nothing accumulates in the water that will interfere with your chlorine later.

The calcium is the honest tradeoff. Every dose adds a small amount of calcium hardness. In soft water that's a mild benefit, since low calcium is aggressive toward plaster and equipment. In hard water — common across much of the Intermountain West — calcium accumulates alongside what's already there and eventually contributes to scale on surfaces and heater elements. It's a slow effect, but it's real, and worth watching if you're shocking weekly all season.

The other property to plan around is pH. Calcium hypochlorite is strongly alkaline, so each application nudges pool pH upward — the opposite of what trichlor tablets do. On a tablet-fed pool the two effects partially cancel out. On a pool sanitized another way, expect to bring pH back down periodically. That's also why the label calls for setting pH to 7.2–7.4 before shocking rather than the usual 7.4–7.6: you're starting slightly low because the product will raise it.

Pro Tip: Shock at night, and the reason is chemistry rather than convenience. Unstabilized free chlorine breaks down rapidly under ultraviolet light, and Burnout 73 contributes no cyanuric acid to protect it — that's the whole point of choosing it. Shock a pool at noon in July and a substantial share of the dose is destroyed by sunlight before it finishes oxidizing chloramines. Apply after dark with the pump running overnight and the chlorine gets eight to ten uninterrupted hours at full strength. It's the same product either way; the difference is whether you get what you paid for.

Coverage Reference

• One 1 lb bag treats up to 16,500 gallons
• A 20,000-gallon pool requires two bags for a full treatment

Treatment Frequency

• At least once per week during periods of heavy use, or when water temperatures are above 80°F
• Once every two weeks in a residential pool receiving normal usage

Important Handling Note

Never add water to product. Always add product to large quantities of water to fully dissolve. Broadcasting the granules directly over the deep end of the pool satisfies this — the pool is the large quantity of water. What must never happen is adding a small amount of water to the product in its container or a bucket.

Shock Treatment and Superchlorination

1. Adjust pH between 7.2 and 7.4 prior to shocking or superchlorination.
2. Add this product at night or when the pool is not in use.
3. Maintain operation of your pump and filter throughout.
4. Broadcast the dry granules over the surface of the water at the deepest end of the pool while the pump is running.
5. Brush any undissolved granules off pool surfaces so they don't rest against the finish.
6. Do not enter the pool until the free chlorine residual has dropped to 4.0 ppm or less, as measured using a suitable test kit.
7. Between treatments, continue to maintain proper water balance and sanitizer level as recommended on the label of your normal pool sanitizer.

When to Superchlorinate

• Weekly during heavy use or when water temperature exceeds 80°F
• Every two weeks under normal residential use
• After a party or heavy bather load
• After heavy rain
• When water smells strongly of chlorine or irritates eyes — both signs of chloramine buildup
• When water looks dull despite normal sanitizer and balance readings
• At opening and closing

Storage and Handling

• Store in a cool, dry, well-ventilated area away from direct sunlight, heat, and open flame
• Keep bags sealed and completely dry — moisture degrades calcium hypochlorite and can release chlorine gas
• Store well away from trichlor tablets, acids, and organic materials — this separation is a fire-safety requirement, not a preference
• Keep out of reach of children and pets
• Never return unused product to a bag once it has contacted anything else
• Avoid breathing dust; broadcast downwind of yourself on a breezy day
• Read and follow all label precautions, first aid, and disposal directions before use

Pro Tip: Match your shock to your stabilizer reading and you'll stop fighting your pool in late summer. Test cyanuric acid at opening and again mid-season. If it's low, a stabilized dichlor shock helps by adding protection along with the chlorine. If it's already at or above the 30–50 ppm range — which it will be on any pool fed by trichlor tablets — switch to an unstabilized cal hypo shock like this one and stop adding stabilizer you don't need. That single decision is the difference between a pool that holds chlorine in August and one that doesn't, and it costs nothing but paying attention to a number most people never test twice.

• Brand: BioGuard
• Product Type: Calcium hypochlorite superchlorinator
• Form: Quick-dissolving granular
• Net Weight: 1 lb
• Manufacturer Part Number: 22860BIO
• Active Ingredient: Calcium hypochlorite, 73%
• Other Ingredients: 27%
• Concentration: Highest percentage calcium hypochlorite in the BioGuard shock line
• Coverage: One bag treats up to 16,500 gallons
• Stabilized: No — contributes no cyanuric acid
• Effect on pH: Raises pH
• Effect on Calcium Hardness: Raises calcium hardness
• Target pH Before Use: 7.2–7.4
• Frequency, Heavy Use or Above 80°F: At least once per week
• Frequency, Normal Residential Use: Once every two weeks
• Application Method: Broadcast dry granules over the deep end with the pump running, at night or when the pool is not in use
• Swim Return: When free chlorine has dropped to 4.0 ppm or less
• Handling Rule: Never add water to product — always add product to large quantities of water
• Suitable Surfaces: All pool surfaces
• Sanitizer Compatibility: Chlorine, bromine, and salt generator pools
• Never Store or Mix With: Trichlor tablets or any other chlorine product — fire and explosion hazard
• Not For Use In: Biguanide pools, spas, or hot tubs
• Shipping Classification: DOT-regulated — ground shipping only

Pool Types and Surfaces

• In-ground and above-ground pools
• All pool surfaces — plaster, gunite, vinyl liner, fiberglass, and painted
• Sand, cartridge, and DE filtration

Sanitizer Programs

• Chlorine pools — the intended application
• Bromine pools — compatible as a superchlorinating oxidizer
• Salt chlorine generator pools — compatible; a salt pool still benefits from periodic shocking

How It Compares to Other BioGuard Shocks

• Versus a lower-percentage cal hypo shock: same chemistry and the same unstabilized advantage, but Burnout 73 is substantially more concentrated. Choose 73 for coverage per bag and maximum oxidizing power; choose the lower-percentage version when it's packaged as a multi-functional weekly maintenance shock with added clarifier.
• Versus a dichlor-based shock: dichlor is stabilized and adds cyanuric acid with every dose, which protects chlorine from sunlight but accumulates permanently. Burnout 73 adds none. Choose dichlor when stabilizer is low; choose this when it's already adequate or high.
• Versus non-chlorine shock: a non-chlorine oxidizer contains no chlorine at all, adds no stabilizer and no calcium, and doesn't bleach — but it isn't a disinfectant and won't clear algae. Burnout 73 does the sanitizing work a non-chlorine shock can't.
• On pH: Burnout 73 raises pH. Trichlor tablets lower it. On a tablet-fed pool the two partially offset each other.
• On hardness: Burnout 73 adds calcium. If your calcium hardness is already high, factor that into how often you use it.

Critical Safety Incompatibilities

• Never allow contact with trichlor tablets or any other chlorine product. Calcium hypochlorite and trichlor can react to cause fire or explosion. This applies to mixing, to sharing a scoop, and to storing them near each other.
• Never add to a skimmer, feeder, or floater, particularly one holding tablets. Broadcast over open water in the deep end.
• Never mix with acids, other pool chemicals, or organic materials. Add each product separately with circulation between additions.
• Never add water to the product. Always add product to large quantities of water.
• Biguanide pools — do not use. Chlorine destroys biguanide sanitizer.
• Spas and hot tubs — this is a pool product dosed by the pound. Use a spa-specific shock.