The hot tub routine is short. Ten minutes a week and an hour every few months.
What makes it feel harder than it is: the jobs aren't on a fixed calendar the way pool jobs are. A tub used every night needs more than one used twice a month, and the schedule has to follow the use rather than the date.
Key takeaways
- Dose after use, not on a schedule. The demand comes from bathers, not from the calendar.
- Shock weekly. Bullfrog says so, and Hot Spring requires it on tubs with its silver purifier.
- A rinsed filter is not a clean filter. Oils need a chemical soak, and a hose will not touch them.
- Drain on your maker's interval, or sooner if a dissolved-solids test reads 1,500 ppm over your fill water.
- Going away? Turn it down, not off. Hot Spring and Bullfrog both say about 80°F.
After every soak
This is the one that matters most.
Add sanitizer with the jets running and the cover off. The bathers created the demand, so this is when it needs replacing. Hot Spring's manual says a tub used for a whole afternoon or evening needs extra sanitizer. Waiting until your weekly check means the water spends days under-sanitized at body temperature, which is how a rash starts. Our hot tub chemical picks cover what to keep on the shelf for it.
Leave the cover open for twenty minutes. That's Sundance's figure after a shock or a pH chemical, and Hot Spring's after a shock, so the gas can vent instead of discoloring the cover and pillows. Bullfrog says thirty after a shock.
That's it. Under a minute of actual work, and then some waiting.
Every week
Weekly hot tub routine
Every four weeks
Clean the filter. Power off, cartridge out, then hose it from the top down, working between the pleats. Rinsing removes debris. It does not remove body oil, lotion or the greasy film that blinds a cartridge, so follow it with a soak in filter cleaner and a second rinse.
That's the spa makers' interval, not a guess. Hot Spring and Caldera say every four weeks and to use the degreaser each time, Jacuzzi and Sundance say monthly, and Bullfrog says every 3 to 6 weeks for its X Series. Heavy use means sooner. Caldera's manual warns that a clogged filter can trip the high-limit thermostat, which is one reason a tub stops heating.
A second cartridge makes this painless. Unicel recommends alternating two sets, so one goes in clean while the other soaks, and the tub isn't switched off overnight.
Clean the cover. Hot Spring, Jacuzzi and Bullfrog all say monthly. Mild soap on the top, rinsed off before it dries, and water only underneath: Hot Spring and Jacuzzi both say no soap on the underside.
Go deeperHow to clean a hot tub filterEach spa maker's steps, what to soak it in, the acid question, and when to replace it.Every three months
Drain, clean and refill, or on your own maker's interval. More on the timing below.
Check the cover. Lift it. If it's noticeably heavier than it was, the foam core has taken on water, and a waterlogged cover insulates poorly and costs you money every day.
Look at the jets and pillows. Scale on the jet faces points to calcium and pH running high, which Caldera's manual names as the cause of scale. On the pillows, look for discoloring: Hot Spring and Bullfrog both warn that sanitizer gas trapped under the cover damages them, which is why the cover stays open after a shock.
When to actually drain
Every maker gives an interval, and they differ. Jacuzzi and Sundance say about every three months. Hot Spring says about four, depending on how much soap gets into the water. Bullfrog says every one to four months. Heavy use means sooner.
Dissolved solids only go up. The Alliance lists where they come from: the fill water, the chemicals you add, bathers and evaporation. Hot Spring adds that no chemical you add can oxidize soap, only ozone can. Fresh water is the only reset.
The signs of water that's overdue, from the makers' own manuals:
- Foam you can't control, which is Jacuzzi's and Sundance's first sign
- Water without its normal feel or sparkle, even with every reading in range
- An unclean feeling on your skin after a soak, which Hot Spring says nothing fixes but fresh water
- Sanitizer that seems to do less, which the Alliance links to high dissolved solids
That's not a chemistry problem you can dose your way out of. It's water at the end of its life.
The formula you'll see elsewhere
You'll find a rule that divides the tub's gallons by three, then by the average number of bathers a day, to get the days between drains. It comes from a 2013 Spasearch buyer's guide that Hot Spring sponsored, rather than from any spa maker's manual.
The Alliance publishes a formula that looks similar but isn't. It divides by every bather since the last drain, not by the daily average, so for the same use it calls for fresh water far sooner. Neither matches the makers' intervals in months, so I go by the maker's interval and the TDS test.
Go deeperDraining and refilling, step by stepPower off first, what to clean the shell with, and how to refill without an airlock.Once a year
Consider a line purge at a drain. None of the makers' manuals asks for one, but the CDC says biofilm in plumbing can shelter Legionella and Pseudomonas from sanitizer. If you use one, follow its label and keep the filter in.
Inspect the cabinet. Look for damp, for rodent damage, and at the pump union seals.
Check the ozone system if you have one. Its parts wear out: Jacuzzi's control panel counts down to when its ozone unit needs replacing, and Bullfrog says to ask your dealer about maintaining and replacing its ozone parts. A dead one doesn't stop the tub working. You just end up doing more of the sanitizing with chemicals.
Looking after the cover
When a cover's foam cores take on water, it gets heavier, harder to lift, and stops insulating. The makers' manuals agree on how to look after one:
- Clean it monthly. Hot Spring, Jacuzzi and Bullfrog all say so.
- Keep soap off the underside. Hot Spring says to rinse it with water only and wipe it dry, and Jacuzzi says no soap there.
- Nothing harsh on top. Jacuzzi rules out solvents, abrasive cleaners, strong detergents, and anything with silicone or alcohol. Bullfrog says to condition the fabric with an outdoor fabric protectant that is never petroleum-based.
- Leave it open after a shock. Twenty minutes for Hot Spring, thirty for Bullfrog. Hot Spring calls cover damage from trapped oxidizer gas chemical abuse, and its warranty doesn't cover it.
- Hold sanitizer at your maker's range, not above it.
- Keep the weight off. Don't sit or stand on it. Bullfrog says to clear snow deeper than 2 inches, and Jacuzzi that clearing snow helps keep the foam cores from breaking.
Leaving it for a week, or a month
Three to five days: Hot Spring says to balance the pH and shock before you go, lock the cover, then shock and balance again when you're back.
Five days to two weeks: a day before you leave, set the temperature to its lowest, about 80°F. Hot Spring says dichlor stays effective substantially longer in 80°F water than in hot water. Balance the pH and shock, and when you're back, shock again, reset the temperature, and wait until the chlorine is below 5 ppm. Bullfrog gives the same 80°F for two to six weeks away, says it cuts the running cost, and allows about four hours to heat back to 100°F.
Longer: Hot Spring says that past two weeks with no one looking after the water, you should drain or winterize; with its FreshWater III ozone system, four weeks. Bullfrog says that for six weeks or more, or whenever no one can look after it weekly, use its Vacation mode, which holds the set point 20°F lower, or winterize. Draining for storage means following your manual's winterizing steps, not simply emptying the shell.
The one combination to avoid entirely is heater off, water in, cold climate, nobody home. Hot Spring notes that even its ozone system doesn't protect against freezing.
The two jobs worth not skipping
Soaking the filter, not just rinsing it. Hot Spring and Caldera call for the degreaser every time, because a hose doesn't shift oil. A cartridge that only gets rinsed looks clean and passes less and less water.
Changing the water on schedule. Everything gets harder in old water, chemicals stop working, and it's easy to conclude the tub is faulty when the answer is a hose and an afternoon.
Neither is complicated.
Go deeperWhat all of this costsElectricity, chemicals, filters, and the reserve worth setting aside.The spa routine kit
- Check price
AquaChek Select Connect test strips
Fine for a quick mid-week pH check. Not for decisions that cost money.
- Check price
filter cleaner
A hose rinse leaves the oils behind. This is what gets the greasy film.
Frequently asked questions
How often should you change hot tub water?
On your maker's interval: about every three months for Jacuzzi and Sundance, about four for Hot Spring depending on how much soap gets into the water, and every one to four months for Bullfrog, sooner with heavy use. The Pool & Hot Tub Alliance adds a test: drain once the water's total dissolved solids are 1,500 ppm above what the fill water read. You may also see a rule of gallons divided by three, then by bathers a day. That comes from a 2013 buyer's guide, not a spa maker, and the Alliance's own formula gives very different answers.
How often should I clean my hot tub filter?
About every four weeks. Hot Spring and Caldera say every four weeks, Jacuzzi and Sundance monthly, and Bullfrog every 3 to 6 weeks for its X Series, sooner with heavy use. Hot Spring and Caldera also say to use a filter degreaser every time, because a hose removes debris but not the body oil and lotion in the pleats.
Do I need to test hot tub water every day?
Not every day, but before every soak. Hot Spring says to test weekly or each time the tub is used, and Bullfrog says to check the water before each use. Hot water and a small volume mean sanitizer can fall out of range quickly, and testing before you get in is the only way to know what you are getting into.
What happens if you do not drain a hot tub?
Dissolved solids build up, and the water stops behaving. The Pool & Hot Tub Alliance says high dissolved solids make sanitizers less effective and can corrode fittings and stain surfaces. Jacuzzi and Sundance say it's time to drain when you can't control the foam, or the water lacks its normal feel and sparkle even with every reading in range. Hot Spring says soap build-up eventually leaves an unclean feeling on the skin that nothing fixes but fresh water.
Should I turn my hot tub off when not in use?
Turn it down rather than off. For a trip, Hot Spring and Bullfrog both say to set it to its lowest temperature, about 80°F. Bullfrog says that cuts the running cost, and Hot Spring that dichlor stays effective much longer in 80°F water than in hot water. Neither manual says to leave a full tub switched off. Past two weeks with no one looking after the water, Hot Spring says to drain or winterize, and Bullfrog, past six weeks, to use its Vacation mode or winterize.
