How Often Should You Drain and Refill Your Hot Tub?
🧼 How Often Should You Drain and Refill Your Hot Tub?
Spoiler alert: If your hot tub water smells like a high school locker room, it’s already overdue.
Let’s get into the gritty (and bubbly) truth about how often you should drain and refill your hot tub — because nothing ruins a relaxing soak like cloudy water.
📅 The Golden Rule: Every 3–4 Months
Most hot tub manufacturers (and spa pros like us at Polar Springs) recommend draining and refilling your tub every three to four months. That’s under regular use — think 2 to 4 people a few times a week, with basic care and maintenance.
But here’s the good news: if your spa is equipped with advanced water care systems — like an ozonator or UV purification system — you may be able to safely stretch that interval to 5 or even 6 months between drains.
Why? Because these systems help break down organic waste and bacteria before it can build up in the water, reducing the overall burden on your sanitizer and keeping water fresher, longer.
So if you’re rocking ozone or UV , congrats — your spa is equipped with enhanced water purification, which means fewer drain cycles and more relaxing soak time between.
🧪 Why You Can’t Just Top It Up Forever
Even the cleanest person brings a lot into the tub:
Body oils
Sweat
Hair products
Lotions
Laundry detergents from swimsuits
The occasional splash of beer, wine, or sangria ;)
Over time, all of this builds up in the form of Total Dissolved Solids (TDS) — microscopic stuff that your sanitizer can’t remove. As TDS levels rise, your water gets harder to balance and easier to contaminate.
Draining the water is like hitting the reset button. It gives your chemicals a clean slate to work with.
🔍 How to Know It’s Time
If you’re not tracking your last water change, watch for these signs:
Water smells sour or “off”
Foamy bubbles that linger on the surface
Water chemistry that just won’t behave
Cloudy or murky water — even after shocking
If any of those show up, it’s drain day — whether it’s been 3 months or 6.
🧊 What About Winter Draining?
We're in Canada, avoid draining in mid-winter if you can. Schedule your fall water change in late October or early November, and your next one in early spring to avoid mid winter drain and refills.
If you must drain during a cold snap, have a plan our call us at 613-572-2777— towels, buckets, a wet vac, and a few good friends on standby. Ice in the lines is no joke.
✅ Bottom Line
If you’re using standard water care:
Drain every 3–4 months
If your spa has an ozonator, UV-C system, or mineral cartridge system
You may safely stretch to 5–6 months with proper testing and maintenance
Watch your water, trust your nose, and don’t ignore the signs. Fresh water = better performance, happier skin, and a longer-lasting tub.