What About Canada's Cold Winters?
We design our wood burning cedar hot tubs with Canada's brutally cold winters in mind. If you use the tub at least once a week, your water won't drop more than 18 degrees per day except in extreme conditions. Plus, you'll get to enjoy a hot bath in the middle of winter. When you're not using the tub, keep it covered to protect the tub and reduce the risk of the water freezing over.
If you're going on vacation or don't use your hot tub for a while, the water will freeze solid when the temperatures drop below zero. This damages the bottom boards, forcing you to make repairs. Hot tubs are expensive, and you don't want to pay for pricey repairs or replace your hot tub altogether when spring arrives. To keep this from happening, here's a few tips on keeping the water from freezing while you're away.
Use a Heater
If you have electricity, use a stock tank heater to keep the water from freezing. Stock tank heaters raise the water's temperature so it won't freeze even in the bitter cold. Check the wattage to ensure that your stock tank heater doesn't use too much electricity--if it does, try one of these other methods.
Drain the Water
Drain the water until only five inches remain. A small amount of water won't damage the hot tub even if the water freezes over. When you're ready to use the hot tub, fill it with water and fire up the stove. Just make sure you drain the water again afterward or use another method so the water doesn't freeze.
Add Milk Jugs
Don't have enough water to drain and refill the tub? Anchor 8 to 10 empty plastic milk jugs in the hot tub at varying levels. When the water freezes and expands, the milk jugs absorb the shock so the ice won't damage the tub. Afterward, you can get back to enjoying your tub when the ice melts.
Use an Inner Tube
Similarly, you could secure a partially inflated inner tube to the bottom of the tub with rope. The inner tube will absorb the shock as the ice expands so it won't damage the bottom boards. Make sure you tie down the inner tube so it remains submerged--if it floats to the top, it won't protect your tub from damage.
Build a Fire
When a few inches of ice appear on the surface of the water, build a small fire and let the stove heat gradually until it melts the ice. A few inches of ice won't damage the tub as long as you melt it before the water freezes solid. Just make sure you keep an eye on your tub--ice forms more quickly than you'd think, especially when the temperatures drop.
Melt the Ice
If the water freezes completely, your only option is to melt the ice. You could start a fire, but add water to the top of the surface while you melt the ice. Otherwise, the ice could melt too quickly and expose the stove to air, melting the aluminum. Adding water protects the stove while you melt the ice. Afterward, get in the hot tub at least once a week or use one of the above methods so the water doesn't freeze solid again.