Hot Tub Serum Total Maintenance 2L | Biofilm Care

• 1 x Hot Tub Serum Total Maintenance Watercare (2 Liter bottle; approximately 24 weekly doses)

• Value size — 2 Liters provides about 24 weekly doses (4–6 months for most spas)
• Prevents biofilm — stops bacterial buildup inside plumbing and jets before it starts
• Boosts your sanitizer — disperses bacteria so chlorine or bromine works more effectively
• Reduces chemical use — a more effective sanitizer means you use less of everything else
• Softer, clearer water — keeps water clean, soft, and fresh-smelling week to week
• Works with every system — compatible with chlorine, bromine, salt, biguanide, and mineral

The active ingredient is an EPA-registered biocide (a quaternary ammonium compound). Circulated through your spa each week, it works deep in the plumbing lines to keep biofilm from establishing on the interior surfaces — the pipes, pump, and jets you can't see or scrub. By denying bacteria that protected foothold, it keeps the whole system cleaner between water changes.

At the same time, it makes your primary sanitizer more efficient: by dispersing bacteria in the water, it lets your chlorine or bromine reach and neutralize microbes more easily, so your sanitizer isn't fighting an uphill battle. That's why owners find their sanitizer lasts longer and their water clears faster. It's important to understand this is a supplement to your sanitizer, not a sanitizer itself — it helps your sanitizer do its job rather than replacing it.

Pro Tip: For a truly fresh start, pair Total Maintenance with a plumbing purge. If your spa has never been deep-cleaned (or you're refilling), run the brand's Total Cleanse purge before you drain, then keep the clean plumbing that way with weekly Total Maintenance. Purge to remove existing biofilm, maintain to keep it from ever coming back.

Always add chemicals to water, never water to chemicals. Balance your hot tub water to industry-standard levels — total alkalinity 80–140 ppm, pH 7.4–7.6, and calcium hardness 150–350 ppm — and always maintain an EPA-approved sanitizer at the recommended level.

1. With the circulation running, add 1 fl oz (30 mL) per 100 gallons of spa water.
2. Repeat every 7 days, trying to add it on the same day each week. Do not over-dose.
3. A small amount of foaming after application is normal. If excessive foaming occurs, reduce the dosage accordingly.
4. Wait about 2 hours before entering the water after application.
5. Test your water weekly with a reliable kit or strips, and rinse your filter cartridge(s) regularly for best performance.

If water becomes cloudy, foamy, discolored, or develops an odor, shock the water and increase your sanitizer level; if poor conditions persist, perform a full cleanout with the brand's Total Cleanse.

Pro Tip: Pick a "Serum day" and stick to it. This product rewards consistency — a weekly dose on the same day (say, every Sunday) keeps biofilm from ever getting a foothold. Tie it to something you already do weekly, like testing your water or your regular shock, and it becomes an effortless habit that keeps the plumbing spotless.

• Brand: Hot Tub Serum (Serum Watercare)
• Manufacturer: Unique Solutions, Inc.
• Product Type: Weekly biofilm-prevention water care / sanitizer booster
• Form: Liquid (concentrated)
• Net Size: 2 Liters
• Coverage: Approximately 24 weekly doses (about 4–6 months for most spas)
• Active Ingredient: Alkyl dimethyl benzyl ammonium chloride (ADBAC), 9.06%
• EPA Registration: EPA Reg. No. 84409-2
• Function: Prevents plumbing biofilm; boosts sanitizer effectiveness; softens water; helps control pH swings; helps prevent white water mold
• Dosage: 1 fl oz (30 mL) per 100 gallons every 7 days
• Water Balance Targets: TA 80–140 ppm, pH 7.4–7.6, calcium hardness 150–350 ppm
• Reentry: Wait about 2 hours after application before entering
• Not a Sanitizer: Use with an EPA-approved sanitizer; do not let sanitizer run out
• Chemical Tolerance: Unaffected by out-of-range pH, cyanuric acid (CYA), or common oxidizers
• Compatible Systems: Chlorine, bromine, salt/SWG, biguanide, and mineral (The Frog, @ease, Nature2)
• Warranty Program: 2 Liter size qualifies for Serum Watercare's Lifetime Jet Warranty via authorized dealer auto-ship
• Best Paired With: Hot Tub Serum Total Cleanse (plumbing purge) at drain-and-refill
• Storage: Keep from freezing; store in original container out of reach of children
• Application Note: Add chemicals to water; add products one at a time; rinse and dry the measuring cup between additions

Hot Tub Serum Total Maintenance is compatible with all sanitizing systems — chlorine, bromine, salt/SWG, biguanide, and mineral systems (including The Frog®, @ease®, and Nature2®). It's designed to layer on top of whatever sanitizer you already use.

It's also unusually forgiving chemically: it's not affected by pH outside the 7.2–7.6 range, by cyanuric acid (CYA), or by common oxidizers, so it keeps working even when your water chemistry drifts. It works alongside your balancers (keep TA, pH, and calcium hardness in range) and a reliable test kit or strips. As part of a routine, it's the maintenance follow-up to the brand's Total Cleanse purge. Add chemicals one at a time, rinsing and drying your measuring cup between products.