BioGuard SilkGuard Complete 1" Tabs | Sanitizer

• 1 x BioGuard SilkGuard Complete 1" Chlorinating Tablets, 4.5 lb container
• Full manufacturer label with dosing rates, start-up directions, and safety information

A 4.5 lb container holds roughly 120 tablets, or about four and a half doses at 16 oz per 10,000 gallons.

Sized for Small Pools and Small Dispensers

The 1" format fits floaters and feeders that won't accept a 3" tablet, and it gives finer control over dosing in smaller water volumes where a single large tablet is simply too much chlorine at once.

SilkGuard Technology — Softer Water, Protected Surfaces

Bonds to hard water components and metal surfaces to soften how the water feels while shielding the pool finish and equipment from scale formation, corrosion, and metal staining.

SmartGuard Technology — Longer-Lasting Dissolution

Regulates how quickly each tablet breaks down, extending tablet life compared to conventional trichlor and delivering a steadier residual rather than a spike-and-fade cycle.

SunShield Technology — UV Protection for Your Chlorine

Shields the free chlorine residual from ultraviolet breakdown, which is the single largest source of chlorine loss in an outdoor pool and the reason unprotected chlorine fades through a sunny afternoon.

Algae-Killing Crystals

A copper-based algae preventative built into every tablet, working continuously to stop algae before it establishes rather than treating a bloom after the fact.

Works in Skimmers, Feeders, and Floaters

Designed for all three application methods, so it fits whatever dispensing setup the pool already has.

84% Available Chlorine

A concentrated trichlor formulation delivering a strong, stabilized residual, so the small tablets still carry full sanitizing strength.

Same Formula as the 3" Tablet

Identical active ingredients and identical technologies — the only difference is tablet size and how finely you can meter the dose.

The primary active ingredient is trichloro-s-triazinetrione — trichlor — at 91.57%, yielding 84% available chlorine. As water flows over a tablet, the trichlor dissolves gradually and releases hypochlorous acid, the active form of chlorine that destroys bacteria and other microorganisms by disrupting their cell structure.

Tablet size changes the physics, not the chemistry. Dissolution happens at the surface, so what governs how fast a tablet gives up its chlorine is the ratio of surface area to mass. Break the same weight of trichlor into many small tablets instead of a few large ones and you dramatically increase total surface area. That means 1" tablets dissolve more readily and respond faster to a feeder adjustment, while 3" tablets release more slowly and last longer between refills. Neither is better in the abstract — it depends entirely on how much water you're treating and how much dispenser capacity you have.

Trichlor is a stabilized chlorine source, contributing cyanuric acid to the water as it dissolves. Cyanuric acid works as sunscreen for free chlorine, slowing UV breakdown so each tablet's chlorine stays active longer. SunShield Technology builds on that principle. The tradeoff is that stabilizer accumulates permanently and only comes down through dilution.

SmartGuard governs the physical dissolution rate, metering the tablet out rather than releasing chlorine as fast as water contact allows. SilkGuard works through sequestration — binding dissolved calcium, metals, and hard water minerals so they stay in solution instead of precipitating onto surfaces as scale or depositing as stains. That same binding action protects metal equipment from corrosion and produces the softer feel swimmers notice.

The copper sulfate pentahydrate component, equal to 0.25% metallic copper, releases copper ions steadily as the tablet dissolves. Copper interferes with algae cell metabolism directly, adding an algae-control mechanism chlorine alone doesn't provide.

One property to plan around: trichlor is strongly acidic, with a solution pH well below 3. Continuous tablet feeding pulls pH and total alkalinity downward over the season. That's normal and expected, but it has to be corrected rather than ignored.

Pro Tip: Never throw tablets directly into the pool. A tablet resting on the floor creates an intensely acidic, highly concentrated spot of chlorine right against the finish, and the mark it leaves is permanent — bleaching on vinyl, etching on plaster, staining on colored surfaces. This matters more with 1" tabs than most people expect, because a small tablet is easy to drop and easy to lose track of. Tablets belong in a skimmer, feeder, or floater where flowing water dilutes them immediately. If one slips out of a floater, retrieve it right away rather than letting it finish dissolving where it landed.

Dosage Reference

• Start-up: 16 oz (approximately 27 tablets) per 10,000 gallons
• Routine maintenance: 16 oz (approximately 27 tablets) per 10,000 gallons per week, or as needed
• Target free available chlorine: 1–4 ppm at all times

Before You Start

1. Confirm all pool equipment is operating properly.
2. Clean or backwash the filter following your equipment manufacturer's directions.
3. Adjust pH to 7.2–7.6.
4. In chlorinated pools, add stabilizer as needed to establish a minimum cyanuric acid level of 30–40 ppm, which reduces the degrading effect of sunlight on the chlorine residual.
5. If the water is cloudy or green, superchlorinate with an appropriate shock product until the pool is clear before starting tablet feeding. Tablets maintain a residual; they don't recover a failed pool.
6. When using other products alongside this one, follow the directions on those labels as well.

Start-Up and Ongoing Feeding

1. Add 16 oz of product (approximately 27 tablets) per 10,000 gallons of pool water to your skimmer, feeder, or floater.
2. Adjust the feeder or floater per its manufacturer's instructions to establish a free available chlorine level of 1–4 ppm.
3. Allow the water to circulate, then test the free available chlorine level.
4. Once free chlorine is holding at 1–4 ppm, add the preventative algaecide appropriate to your pool.
5. Reload weekly, or as needed, at the same rate to hold the residual.
6. Check the dispenser often and refill before it runs empty. Sunlight, rainfall, water temperature, bather count, and how often the pool is used all change how fast the residual is consumed, so intervals will shift through the season.

Safety Requirements

• Do not add any other chemical into the skimmer, feeder, or floater while this product is in use. Fire or explosion may result.
• Do not throw tablets directly into the pool. Direct contact will damage pool surfaces and materials.
• Re-entry into the pool is prohibited when free available chlorine exceeds 4 ppm, due to risk of bodily injury. Test before swimmers enter.
• Do not allow the product to come into direct contact with pool surfaces or materials.

Storage and Handling

• Store in a cool, dry, well-ventilated area away from direct sunlight, heat, and open flame
• Keep the container tightly closed and the product completely dry — moisture releases chlorine gas
• Store separately from other pool chemicals, especially calcium hypochlorite shock, acids, and organic materials
• Keep out of reach of children and pets
• Never return a used or wet tablet to the original container
• Read and follow all label precautions, first aid, and disposal directions before use

Pro Tip: Test cyanuric acid mid-season, not just at opening. Every trichlor tablet adds stabilizer permanently, and a pool fed continuously all summer can drift far above the 30–40 ppm target without anyone noticing. Once cyanuric acid climbs past roughly 100 ppm, free chlorine becomes progressively less effective at the same test reading — the pool looks properly chlorinated and behaves like it isn't. Watch pH and total alkalinity too, since trichlor is strongly acidic and continuous feeding pulls both downward. A pool that "stopped holding chlorine" in August is usually stabilizer-locked, and no amount of additional product will fix it. Dilution will.

• Brand: BioGuard
• Product Type: Multi-benefit chlorinating tablets
• Form: 1" slow-dissolving tablets
• Net Weight: 4.5 lb
• Manufacturer Part Number: 52370BIO
• Approximate Tablets per Container: 120
• Active Ingredient: Trichloro-s-triazinetrione, 91.57%
• Secondary Active: Copper sulfate pentahydrate, 0.99% (equal to 0.25% metallic copper)
• Other Ingredients: 7.44%
• Available Chlorine: 84%
• Stabilized: Yes — contributes cyanuric acid to the water
• Proprietary Technologies: SilkGuard, SmartGuard, and SunShield
• Algae Control: Copper-based algae-killing crystals
• Start-Up Dose: 16 oz (about 27 tablets) per 10,000 gallons
• Maintenance Dose: 16 oz (about 27 tablets) per 10,000 gallons weekly, or as needed
• Target Free Chlorine: 1–4 ppm
• Target pH: 7.2–7.6
• Minimum Stabilizer Level: 30–40 ppm
• Application Methods: Skimmer, in-line or off-line feeder, or floater
• Suitable Surfaces: Plaster, gunite, vinyl liner, fiberglass, painted
• Best Suited To: Smaller pools and dispensers sized for 1" tablets
• Not For Use In: Biguanide pools, spas, or hot tubs
• System Role: Step 1 of the BioGuard 3-Step Care System
• Shipping Classification: DOT-regulated — ground shipping only

Application Methods

• Floating dispensers — including small floaters that won't accept a 3" tablet
• In-line and off-line chlorine feeders — adjust output to hold the target residual
• Skimmers — supported by SmartGuard's controlled dissolution

Pool Types and Surfaces

• Small above-ground and in-ground pools — the primary intended use for this format
• Plaster, gunite, vinyl liner, fiberglass, and painted surfaces
• All pump types, including single-speed, two-speed, and variable-speed
• Sand, cartridge, and DE filtration

Choosing Between 1" and 3" Tablets

• Choose 1" tablets for smaller pools, small floaters, and any dispenser sized for 1" tabs. The finer increments make it much easier to hold a steady residual without overshooting.
• Choose 3" tablets for larger pools and larger-capacity feeders. Fewer tablets to handle, longer intervals between refills, and generally better value per pound of chlorine on a big pool.
• The formula, active ingredients, and available chlorine are identical between the two. This is a sizing decision, not a chemistry one.

Water Care Programs

• Traditional chlorine pools — the intended application, and Step 1 of the BioGuard 3-Step Care System
• Salt chlorine generator pools — can supplement generator output during heavy demand or cell downtime, though continuous use raises stabilizer levels; check your generator manufacturer's guidance first

Important Incompatibilities

• Biguanide (non-chlorine) pools — do not use. Chlorine and biguanide chemistry destroy each other, producing cloudy water, filter fouling, and a failed sanitizer residual.
• Spas and hot tubs — this is a pool product. Trichlor tablets are too aggressive and too acidic for the small, hot volume of a spa, and the small tablet size does not change that. Use a spa-specific sanitizer.
• Never combine with other chemicals in a skimmer, feeder, or floater. Mixing trichlor with another product — calcium hypochlorite above all — in a confined space can cause fire or explosion.
• Not suited to pools already high in cyanuric acid. Every tablet adds more. If stabilizer is already elevated, an unstabilized chlorine source is the better choice until levels come down through dilution.