Think Crucial Toilet Tank Cleaner Concentrate - 35% Citric Acid, 8 Uses, Bleach-Free, No Blue Dye, Septic Safe - 16 fl oz

Brand: Think Crucial

<h3>About Think Crucial</h3> <p>Think Crucial makes concentrated cleaning solutions that match the actual chemistry of your problem. THE TANK BUSTER uses 35% citric acid - the scientifically correct chemistry for dissolving mineral scale and chelating iron deposits in toilet tanks.</p> <h3>Why THE TANK BUSTER Works When Drop-In Tablets Don't</h3> <ul> <li><b>Correct Chemistry:</b> Citric acid dissolves calcium carbonate and chelates iron. Bleach-based tablets tint water blue but cannot address mineral deposits.</li> <li><b>Pour-In Dwell Format:</b> Empty the tank, pour 2 fl oz, wait 30 minutes, flush 3 times. Brief dwell contact - no continuous rubber component exposure.</li> <li><b>No Blue Dye:</b> Zero colorants. No blue or teal staining on grout, caulk, or toilet exterior surfaces.</li> <li><b>Septic System Safe:</b> All three ingredients are fully biodegradable. No bleach, no HCl, no harsh oxidizers flushed into your drain system.</li> </ul> <h3>How to Use</h3> <p>Shut off the water supply valve. Flush to empty the tank. Pour 2 fl oz directly into the empty tank. Dwell 15-30 minutes - scrub walls if needed. Turn the supply valve back on and let the tank refill. Flush 3 times to rinse. Repeat quarterly or when staining returns.</p> <h3>Compatible With All Standard Toilet Tanks</h3> <p>Works in modern 1.28-1.6 gallon tanks and older 3.5 gallon tanks. Suitable for porcelain, vitreous china, HDPE, and polypropylene tank components. Use 3 fl oz for larger or older tanks with heavy mineral staining.</p> <h3>Our Promise</h3> <p>Think Crucial stands behind every product. If THE TANK BUSTER does not perform as described, we will make it right. Packaged in USA.</p>

• 8 USES PER BOTTLE - 2-YEAR SUPPLY AT QUARTERLY USE: One 16 fl oz bottle delivers 8 full-tank cleaning doses at the standard 2 fl oz dose. At quarterly use, that's a 2-year supply at just $7.50/year - a fraction of standard drop-in tablet costs.
• REMOVES MINERAL SCALE, RUST & HARD WATER STAINING DROP-IN TABLETS CAN'T TOUCH: 35% citric acid dissolves calcium carbonate, chelates iron deposits, and lifts the brown ring and white scale collar that bleach-based tablets simply cannot address.
• BLEACH-FREE, NO BLUE DYE, NO FUMES - RUBBER-COMPONENT SAFE: Zero bleach, zero chlorine, zero colorants. Pour-in dwell means 30-minute contact then fully flushed - no continuous exposure. No grout staining. No chemical fumes when you lift the lid.
• UP TO 63% CHEAPER PER YEAR THAN LEADING DROP-IN TABLETS - 60% MORE USES: One bottle costs $7.50/year at quarterly use. Leading drop-in brands cost $20+/year. Delivers 60% more uses than standard 5-use formats. The math wins. The chemistry wins.
• 35% CITRIC ACID SUPER CONCENTRATE - HCl-FREE, SEPTIC SAFE, BIODEGRADABLE: Every ingredient is biodegradable and safe for all standard septic systems. No hydrochloric acid. No harsh oxidizers. Packaged in USA. Shut valve, pour, dwell 30 min, flush 3×.

Scent: Unscented
Size: 16 Fl Oz (Pack of 1)
Color: clear