Complete Guide to the FROG System: @ease vs. Serene, How SmartChlor Works, and the FROG Jump Start Guide

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Everything You Need to Know About FROG Water Care—Which System to Choose, the Science Behind Self-Regulating SmartChlor, a Step-by-Step Start-Up With Jump Start, Your Routine, and the Mistakes That Trip Up New Owners

By Leisure Time Inc.  |  October 2026  |  Estimated Read Time: 13 minutes

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If you’ve looked into easier hot tub water care, you’ve met FROG®. For more than 25 years, King Technology has sanitized hot tubs with a simple idea: pre-filled cartridges that kill bacteria two ways—with minerals and a low level of sanitizer—so there’s ‘no mess, no guess, no stress.’ FROG calls the result Fresh Mineral Water®, and owners describe it as cleaner, clearer, softer, and easier. We hear it every week in our showrooms.

But FROG isn’t one product. There are two sanitizing systems (@ease® and Serene®), several formats (floating, in-line, and spa-specific), a patented chlorine called SmartChlor®, a start-up shock called Jump Start®, and a family of support products. This guide pulls it all together: which system to choose, how SmartChlor actually works, exactly how to start up a spa with Jump Start, what your routine looks like afterward, and the common mistakes that cause trouble.

From Leisure Time Inc., with showrooms in Boise, Idaho Falls, and Twin Falls. We carry the full FROG line, we set up spas with it constantly, and we’ll give you the honest version—including when FROG isn’t the right fit.

What Makes FROG Different: Fresh Mineral Water

Traditional hot tub care means spooning in chlorine or bromine, watching levels spike when you add it and crash when you use the tub, and shocking every week to catch up. FROG’s approach replaces that cycle with two things working together:

• FROG Minerals: A mineral cartridge that helps kill bacteria, keeps pH more stable, and conditions the water for a softer feel on skin. It lasts about four months.
• A low, steady level of sanitizer: Either SmartChlor (chlorine, in the @ease system) or bromine (in the Serene system), delivered from a pre-filled cartridge so you never measure or mix.

Because the minerals do part of the sanitizing work, the sanitizer level can run far lower than a standard hot tub—up to 75% less chlorine with @ease, up to 50% less bromine with Serene, measured against the minimum ANSI-recommended 2.0 ppm. That’s the source of the softer water, the lack of odor, and the gentler effect on skin, swimsuits, and spa surfaces.

The FROG Lineup at a Glance

Here’s the full family, so the names stop being confusing:

• FROG @ease® (SmartChlor): FROG’s flagship chlorine-based system. Available as a Floating System (drops into any hot tub), the @ease+™ Floating System (an updated floating design), an In-Line System (built into the plumbing of select spas), a 2-in-1 version, and spa-specific versions for Sundance®, Jacuzzi®, Freeflow®, Fantasy®, and Bullfrog® spas.
• FROG Serene® (bromine): The bromine-based alternative, available as a Floating System or an In-Line System.
• FROG Jump Start®: The start-up shock you use at every fresh fill to establish your initial sanitizer level.
• FROG Maintain®: A single-dose, non-chlorine shock in a pour-and-go pouch for routine shocking.
• FROG @ease Test Strips and FROG Test Strips: Single-color-match strips; the @ease version includes an ‘out indicator’ that tells you when to replace the SmartChlor cartridge.
• Support chemicals: Balancers like TArget (alkalinity), DropH (pH down), and JumpH (pH up), plus SooTHe, StoMPS, Filter Mate, and a Pipe & Jet Cleanser for purging plumbing before a drain.
• The FROG Water Care app: Free for iOS and Android, it reminds you when cartridges are due.

@ease vs. Serene: Which Should You Use?

Both systems create Fresh Mineral Water and both use the same four-month mineral cartridge. The difference is the sanitizer—and that changes your routine.

Our honest take: for most people, @ease is the better choice. The self-regulating SmartChlor means less testing, less shocking (monthly instead of weekly), and an out indicator that removes the guesswork. Serene is the right call if you prefer bromine—some people find it gentler on their skin, it’s very stable in hot water, and if you’re coming from a bromine floater it’s a familiar switch. Either way, you get Fresh Mineral Water and pre-filled, no-mess cartridges.

How SmartChlor Works

SmartChlor is the reason @ease behaves differently from every other chlorine routine, so it’s worth understanding. It’s a unique, patented, EPA-registered form of chlorine with a few key properties:

• It’s slow-dissolving. Unlike dichlor (standard hot tub chlorine), which dissolves fast and gets used up as soon as you get in, SmartChlor releases gradually from the cartridge over weeks.
• It self-regulates. SmartChlor automatically delivers more free chlorine when the water needs it—after a soak, for example—and holds back when it doesn’t. The result is a consistent 0.5 to 1.0 ppm free chlorine at all times, with none of the yo-yo spikes and crashes of hand-dosing.
• It only works with FROG Minerals. At 0.5–1.0 ppm, SmartChlor alone wouldn’t be enough to sanitize a hot tub. Paired with the minerals, which kill bacteria on their own, the combination is a complete system. That’s why the two cartridges are always used together.
• It adds no cyanuric acid. Dichlor leaves behind cyanuric acid (CYA) that builds up over time and reduces chlorine’s effectiveness. SmartChlor doesn’t, which is one reason @ease water stays stable between drains.
• It needs less shock. Because the chlorine level never crashes, there’s less for shock to catch up on—which is how @ease gets away with shocking once a month instead of weekly.

Because SmartChlor runs so low, FROG designed a testing method just for it. The @ease Test Strip’s top pad is a SmartChlor out indicator: if it reads darker than the color on the bottle label, your cartridge is still working; if it’s lighter, it’s time to swap it. Dip for two seconds, shake once, compare—done.

FROG Jump Start: Your Step-by-Step Start-Up Guide

Every FROG system needs a proper start-up at each fresh fill, and FROG Jump Start is the key to it. Jump Start is a chlorine start-up shock with an effervescent, fizzing action that dissolves fast—so the chlorine doesn’t settle on the floor of the spa—to remove organic contaminants from fresh fill water and establish your initial sanitizer residual before the cartridges take over. One packet treats up to 600 gallons, and it comes in every @ease and Serene start-up kit. Here’s FROG’s process:

1. Prepare the spa: Clean or replace your filter cartridges, make sure all equipment is working, and fill with fresh water—FROG recommends filling through the filter standpipe to about half an inch below the pillows.
2. Heat and circulate: Bring the spa to operating temperature and run the pump and filter as your manufacturer recommends.
3. Balance the water—in order: Dip a FROG test strip and balance Total Alkalinity first, then pH, then Calcium Hardness, using FROG TArget, DropH, or JumpH as needed. If hardness is too high, partially drain about six inches and refill with low-calcium water.
4. Add Jump Start: With the jets running, add one Jump Start packet per 600 gallons to establish an initial free-chlorine residual of 0.5–1.0 ppm and clear any contaminants from the fill water. Do this before installing the cartridges.
5. Set the cartridges: Set the mineral cartridge to its maximum setting (6). Set the SmartChlor or bromine cartridge dial to the number that matches your spa’s gallons (or your spa model, for in-line systems)—the chart is in the box.
6. Install them: Snap both cartridges into the floating holder and let it free-float, or load them into the in-line holder in your spa’s filter compartment. Tip: remove the small plastic labels on the bottom of each cartridge first; a stray label can block water flow.
7. Test after 24 hours: Confirm your sanitizer and balance with a test strip. If you’re using a floater, remember to remove it while you soak and put it back when you’re out.

Your Routine After Start-Up

Once the system is running, the ongoing routine is light. Here’s the rhythm for @ease (Serene is the same except for weekly shocking and bromine cartridge swaps):

• Weekly: Dip an @ease test strip to check the SmartChlor out indicator, pH, alkalinity, and hardness. Adjust balance if needed.
• Every 3–4 weeks: Replace the SmartChlor cartridge when the out indicator says so (about every 2–4 weeks for a Serene bromine cartridge).
• Monthly: Shock with a single pouch of FROG Maintain (weekly for Serene, or more often under heavy use).
• Every 4 months: Replace the mineral cartridge, and drain and refill the spa. Run FROG’s Pipe & Jet Cleanser before draining to purge the plumbing.
• Every soak: If you use a floater, take it out while you’re in and return it when you get out.

Expect your first month to run a little heavier—new spa owners soak more than they think they will, and more bathers means the cartridge works harder. If your spa is over 400 gallons with heavy use, FROG suggests turning the SmartChlor dial up one number.

Common Mistakes and Troubleshooting

FROG is easy, but these are the issues we hear about most—and they’re all avoidable:

• ‘I’m burning through SmartChlor cartridges.’ Almost always biofilm in the plumbing consuming your sanitizer. The fix: a pipe purge with FROG’s Pipe & Jet Cleanser, then a drain and refill. Make the purge a habit before every drain.
• Switching from dichlor without draining. If your water has a high cyanuric acid level from dichlor, @ease won’t perform until you drain and refill. Start fresh.
• Running minerals without SmartChlor—or vice versa. They’re a system. Replace both on schedule.
• Forgetting to return the floater. Pull it out to soak, but put it back every time, or the water goes unsanitized.
• Wrong dial setting. Set the cartridge to your actual gallons (or model). Too low and it can’t keep up; the fix is one number at a time.
• Leaving the cartridge labels on. Peel the small labels off the bottom before installing—a loose label can block the holder’s outlet.
• Neglecting balance. Minerals help stabilize pH, but they don’t replace balancing. A weekly strip keeps you ahead of it.

Which Spas Can Use FROG?

Nearly any of them. The floating systems work in hot tubs from 150 to 600 gallons regardless of brand, and the in-line system is built into many spas at the factory. FROG also makes dedicated versions for Sundance, Jacuzzi, Freeflow, Fantasy, and Bullfrog spas that fit their filter compartments.

Two notes from our showroom experience. First, on a Sundance spa, FROG @ease pairs beautifully with the built-in CLEARRAY® Active Oxygen® system—CLEARRAY handles oxidation and SmartChlor handles the sanitizer residual, which is why FROG makes a Sundance-specific version. Second, on a Hot Spring or Caldera spa, FROG works, but the built-in FreshWater® Salt System is usually the better fit. For the full comparison of those three systems, see our water care guide linked below.

Frequently Asked Questions

What’s the difference between FROG @ease and FROG Serene?

Both create Fresh Mineral Water with the same four-month mineral cartridge; the difference is the sanitizer. @ease uses SmartChlor, a patented self-regulating chlorine that holds 0.5–1.0 ppm with up to 75% less chlorine and needs shocking only once a month. Serene uses a bromine cartridge with up to 50% less bromine and weekly shocking. @ease is the easier routine for most owners; Serene is for people who prefer bromine.

How does SmartChlor work?

SmartChlor is a slow-dissolving, EPA-registered form of chlorine that self-regulates—it releases more free chlorine only when the water needs it and holds back otherwise, maintaining a steady 0.5 to 1.0 ppm with no spikes or crashes. It only works in combination with FROG Minerals, which do part of the sanitizing, and it adds no cyanuric acid. That stability is why @ease needs less testing and only monthly shocking.

What is FROG Jump Start, and when do I use it?

Jump Start is a fast-dissolving, fizzing chlorine shock used at every fresh fill. After you balance the water (alkalinity, then pH, then hardness), you add one packet per 600 gallons to remove contaminants from the fill water and establish a 0.5–1.0 ppm chlorine residual before you install the cartridges. It’s included in every @ease and Serene start-up kit.

How often do I replace FROG cartridges?

The mineral cartridge lasts about four months or until you drain and refill. The @ease SmartChlor cartridge lasts about three to four weeks in a typical 400-gallon spa; the Serene bromine cartridge lasts two to four weeks depending on use. The @ease test strip’s out indicator tells you exactly when SmartChlor is spent, and the free FROG app sends reminders.

Why am I going through SmartChlor cartridges so fast?

The most common cause is biofilm in the spa’s plumbing, which consumes sanitizer faster than the cartridge can release it. The fix is a pipe purge with FROG’s Pipe & Jet Cleanser followed by a drain and refill, then a fresh start-up with Jump Start. Heavy bather load or a dial set too low for your spa’s gallons can also shorten cartridge life.

Can I use FROG in any hot tub?

Nearly any. The floating systems work in hot tubs from 150 to 600 gallons of any brand, and FROG makes in-line and spa-specific versions for Sundance, Jacuzzi, Freeflow, Fantasy, and Bullfrog spas. On a Sundance it pairs especially well with the built-in CLEARRAY system. On Hot Spring and Caldera spas, FROG works, but the built-in FreshWater Salt System is usually the better choice.

At Leisure Time Inc., we stock the full FROG line—@ease and Serene systems, replacement cartridges, Jump Start, Maintain, test strips, and balancers—and we start spas up with it every week. Bring us your spa model and a water sample, and we’ll walk you through start-up, dial in your balance, and get your cartridges on a schedule. Simple water care should actually be simple, and with FROG set up right, it is.

No mess, no guess, no stress—that’s FROG done right, with a dealer who’ll help you every step.

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Tags: FROG, FROG @ease, FROG Serene, SmartChlor, FROG Jump Start, Hot Tub Water Care, Fresh Mineral Water, Bromine vs Chlorine, Hot Tub Maintenance, Idaho