Swim Spa Serum | Swim Spa Biofilm Maintenance

• 1 x Swim Spa Serum Total Maintenance (32 fl oz bottle; about 8 weeks in a 2,000-gallon swim spa)

• Built for swim spas — formulated for the large water volumes standard maintenance can't cover economically
• 4x concentrated — dosed at 1 oz per 500 gallons to keep cost down in big systems
• Prevents biofilm — stops bacterial buildup deep inside swim spa plumbing
• Boosts your sanitizer — makes chlorine, bromine, or salt work more effectively
• Reduces chemical use — a more effective sanitizer means less of everything else
• 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 swim spa each week, it works deep in the plumbing lines to keep biofilm from establishing on interior surfaces — the pipes, pump, and jets you can't see or scrub. It works in part by reducing the water's surface tension, making it very difficult for bacteria to attach and form the protective biofilm slime in the first place, and by removing the food sources bacteria need to multiply.

At the same time, it makes your primary sanitizer more efficient: by keeping bacteria from gaining a foothold, it lets your chlorine, bromine, or salt system do its job with less demand. It's important to understand this is a supplement to your sanitizer, not a sanitizer itself — it helps your sanitizer work rather than replacing it.

Pro Tip: Start a fresh swim spa the right way. Before you first use Swim Spa Serum, run the brand's Total Cleanse to purge existing biofilm, drain and refill, and make sure your filter cartridges are clean or new. Starting with clean plumbing and clean filters lets Swim Spa Serum keep it that way from day one.

Always add chemicals to water, never water to chemicals. Balance your swim spa 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.

Startup

1. Before first use, purge with Total Cleanse, then drain and refill with fresh water. Make sure filter cartridges are installed and are clean or new.
2. After balancing, shock the water with an EPA-approved sanitizer and establish your sanitizer level.

Weekly Maintenance

1. With the circulation running, add 1 fl oz per 500 gallons of swim spa water.
2. Repeat every 7 days, on the same day each week. Do not over-dose.
3. A small amount of foaming is normal. If excessive foaming occurs, reduce the dosage accordingly.
4. Maintain sufficient sanitizer at all times — do not let it run out. Rinse filter cartridges regularly with pressurized water.

If water becomes cloudy, foamy, discolored, or develops an odor, shock the water and increase your sanitizer level; if poor conditions persist, clean your cartridge filters and, if needed, perform a full Total Cleanse.

Pro Tip: Pick a "Serum day" and stick to it. A weekly dose on the same day keeps biofilm from ever getting a foothold in all that plumbing. In a 2,000-gallon swim spa, that's about 4 ounces a week — so one 32 oz bottle covers roughly two months. Tie it to your weekly water test and it becomes an effortless habit.

• Brand: Hot Tub Serum (Serum Watercare)
• Manufacturer: Unique Solutions, Inc.
• Product Type: Weekly biofilm-prevention water care for swim spas (sanitizer booster)
• Form: Liquid (concentrated — 4x standard Total Maintenance)
• Net Size: 32 fl oz
• Coverage: About 8 weeks in a 2,000-gallon swim spa
• Active Ingredient: Alkyl dimethyl benzyl ammonium chloride (ADBAC)
• Registration: EPA-registered (Serum Watercare / Hot Tub Serum line)
• Function: Prevents plumbing biofilm; boosts sanitizer effectiveness; softens water; helps control odors and pH swings
• Dosage: 1 fl oz per 500 gallons every 7 days
• Water Balance Targets: TA 80–140 ppm, pH 7.4–7.6, calcium hardness 150–350 ppm
• Intended For: Swim spas and large-volume units only — NOT standard hot tubs (use regular Total Maintenance there)
• Not a Sanitizer: Use with an EPA-approved sanitizer; do not let sanitizer run out
• Compatible Systems: Chlorine, bromine, salt/SWG, biguanide, and mineral
• Best Paired With: Hot Tub Serum Total Cleanse (plumbing purge) at drain-and-refill
• Origin: Made in the USA
• 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

Swim Spa Serum is compatible with all sanitizing systems — chlorine, bromine, salt/SWG, biguanide, and mineral systems. It's designed to layer on top of whatever sanitizer your swim spa uses.

It's specifically for swim spas and other large-volume units — not standard hot tubs, which should use regular Hot Tub Serum Total Maintenance instead. It's the maintenance follow-up to the brand's Total Cleanse purge, and it works alongside your balancers (keep TA, pH, and calcium hardness in range) and a reliable test kit or strips. Add chemicals one at a time, rinsing and drying your measuring cup between products.