How do you prep your hot tub for the winter?

I usually just drain the water, clean the filter, and seal it up tight so nothing gets in during the winter. Pretty simple.
 
Same here. I usually drain the water, clean the filter, and seal it up tight so nothing gets in during the winter. Simple but safe.
 
I usually drain the water, clean the filter, and seal it up tight so nothing gets in during the winter. Simple but safe.
 
I usually just drain the water, clean the filter, and seal it up tight so nothing gets in during the winter. Pretty simple but safe.
 
My routine is pretty simple too. I drain the water, clean the filter, then seal it up tight so nothing gets in. Once that’s done, it’s usually good through the winter.
 
I do a little more than just drain and cover, mostly because I’ve been burned by leftover water freezing before. Before draining, I like to run a proper spa purge to clear the plumbing, you’d be surprised how much stuff is hiding in the lines, and it’s easier to deal with it while there’s still water in the tub.

After draining, I use a wet/dry vac to blow out the jets and suction lines. That extra step gives me peace of mind that there’s no trapped water waiting to freeze and crack something. I’ll also wipe the shell dry and leave the equipment bay slightly open for a day or two so moisture can escape.

Once everything’s dry, clean filter stored indoors, cover secured, then I forget about it until spring. Takes a bit longer upfront, but I’ve never had a winter surprise since doing it this way.
 
When I winterize my hot tub, I keep it simple: I fully drain it, rinse and wipe the shell, then clean the filter (or just swap it). After that I try to get as much water out of the lines/jets as I can so nothing freezes. Finally, I shut the power off, seal it up tight with a clean, dry cover, and check on it once in a while so no water or debris gets in.
 
This thread has a good variety of real-world approaches, but for anyone coming across it later, the fundamentals of winterizing a hot tub tend to be:

1. Balance the basics first
Before anything else, make sure your water chemistry is in range — pH, alkalinity, and sanitizer. If water sits out of balance over winter, it becomes harder to correct later.

2. Shock and clean
A thorough shock treatment helps reduce organics and sanitizer demand. Clean or change filters, and flush lines to remove buildup that could cause issues when water sits cold.

3. Decide how cold it will get
Your specific steps depend on winter temperatures:
  • If you’ll use the tub over winter, keep it filled, balanced, and running with a cover.
  • If you will not use it and expect freezes, physical drain-down and blowing out lines is necessary for protection.
4. Protect plumbing and equipment
For areas where freezing is a real risk:
  • Drain water from jets, pumps, and lines.
  • Use a shop vac or compressor to blow out residual water.
  • Consider adding very small amounts of low-mount antifreeze specifically rated for potable/spa use into the lines.
5. Cover and insulate
A well-sealed, quality cover helps prevent heat loss and debris entry. For extremely cold climates, additional insulation around the cabinet or cover can help reduce freeze risk if you leave water in.

6. Shut-off vs. keep running
  • Keep running: If you’re using it through winter and temps hover above freezing, running with proper chemistry and a good cover minimizes maintenance headaches.
  • Shut off & winterize: If you won’t use it and freezes are expected, thoroughly drain, blow out lines, and protect equipment.
7. Long gaps between checks
Even a winterized spa can benefit from an occasional check-in, especially if temperatures fluctuate or ice builds around plumbing.
 
I used to do the basic drain, clean the filter, throw the cover on and hope for the best. It mostly worked, until one spring when I refilled and immediately had cloudy water and crazy sanitizer demand. Turned out stuff had been sitting in the pipes all winter even though the shell was empty. Warm spells, cold snaps, moisture just hanging out in there.

Now my routine starts before the drain. I run aquadoc spa purge while there’s still water in the tub and let the jets go for a couple hours. First time I did it I was honestly grossed out by what came out, brown foam, stringy gunk, stuff sanitizer never touched. That’s biofilm sitting in the plumbing, and winterizing without clearing it just locks it in. After that I drain, wipe the shell, clean or swap the filter, then blow out the jets and suction lines so there’s no trapped water waiting to freeze.

Once everything’s dry, power off, cover on, done. Takes a bit more time upfront but spring startup is way smoother. pH doesn’t swing as hard, sanitizer holds, and I’m not fighting mystery slime right away. Learned the hard way that winter prep isn’t just about freezing, it’s about what you leave behind when the water’s gone.
 
I learned pretty quickly that winter prep is less about the calendar and more about what kind of winter you actually get. Where I am we bounce between freezes and weird warm spells, so just draining and walking away bit me once. Spring refill was a mess, sanitizer demand through the roof and pH drifting nonstop.

Now I start while there’s still water in the tub. I run a full purge first because anything left in the plumbing just sits there all winter. The first time I did it, the jets pushed out brown foam and stringy gunk I didn’t know existed, which explained a lot. I use aquadoc spa purge, let it circulate with all the jets open, then drain. After that I wipe the shell, pull the filter and clean it indoors, and use a shop vac to blow out the jets and suction lines so there’s no trapped water waiting to freeze.

Once everything’s dry, I shut the power off, crack the equipment bay for a day so moisture can escape, then seal it up with a clean cover. Since doing it this way I haven’t had cracked fittings or gross surprises in spring. The big lesson for me was winterizing isn’t just about freezing temps, it’s about not locking old biofilm and gunk into the plumbing for months. Anyone else notice spring startups are way calmer when the lines were actually clean before shutdown?
 
Most of the replies here lean toward full shutdown, so I’ll add the perspective from someone who stopped fully winterizing once I understood my climate a bit better.

I’m in an area where it dips below freezing at night but warms back up during the day, and what actually caused me trouble wasn’t running the tub, it was moisture sitting still. When I used to drain and seal everything tight, I’d still get condensation in the cabinet and lines during those warm spells, then a freeze right after. That’s when fittings got stressed and spring startups turned into a headache.

What I do now is decide early whether the tub is staying active or truly going dark. If I’m not using it at all, then yeah, purge first, drain, blow out lines, dry everything. But if I think I might use it even once every couple weeks, I keep it filled, balanced, and powered. I turn the temp down, not off, keep alkalinity steady so pH doesn’t drift from aeration, and make sure the pump cycles daily so water never sits stagnant in the plumbing. Clean water moving slowly is way safer than damp pipes doing nothing.

Biggest winter mistake I made early on was mixing approaches, half drained, half sealed, power off. That’s when problems showed up. Pick one path and commit to it based on your temps. Anyone else notice most winter damage happens during those freeze-thaw swings, not the deep cold?
 
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