Why do you need an ice tub?
Since I began my Wim Hof Method journey in 2017 in Singapore, one of my first realizations is that our cold water could never be cold enough to give any substantial shock that the Cold Exposure pillar of the method needed us to be subjected to. Fortunately enough, I came across this gem of an ice tub that was being sold by a friend. Two years of trial and error, many types of ice bath accessories and countless wonderful 5°C/41°F immersions later, I've received many queries about how this is set up, and so with what I believe to be an ideal arrangement (finally), I'm putting together an explanation of a simple, low-maintenance way to set up your own ice bath / ice tub at home.
What brand/model are you using?
The model I am using is a Kadeka 350L chest freezer. Brand new units go for about SGD 750 / USD 500. One of the main considerations is "Will this fit a human body?" Something I'd rather not ask shopkeepers, so I made a few measurements of my shoulders and height and concluded that an ideal Width X Depth X Height is around 120cm long, 75cm wide and 80cm deep (3.9ft x 2.4ft x 2.6ft).
Do you always keep the power on?
One of the most power-hungry devices at home would be the fridge, so a deep freezer isn't far off especially when it's desperately trying to keep a 30°C temperature difference. I got myself a Xiaomi Smart Plug that was able to provide power and allow me to control it with my phone. I can program it to switch on for certain numbers in the day, and the unit's insulation can keep the water cold through the night.
Unfortunately we use a UK 3-pin plug here while the Chinese smart plug only comes in their dual flat pin format, so I've resorted to adding two adapters which makes it annoyingly long. It still works but I have to add some makeshift plastic cover to shelter it from the rain at the balcony.
[Update 14 Dec 2020]
I've changed this from a Xiaomi plug to a Wifi Smart Plug like below, so adaptors are not needed anymore and it uses a dedicated smartplug app instead of the Chinese MiHome app which sometimes gets confusing.
What do you do before filling with water?
Before filling up, I got some high quality silicon and after watching 5 minutes of Youtube, became a qualified silicon applicator. Not knowing how well insulated the internals are against the electricity, I applied the silicon on every visible edge, then smoothed it with fingers. Make sure the silicon does not touch your clothes, it is almost impossible to get rid of!
Fill it up 2/3 of the way, until the water just about reaches the thermostat so you can check the temperature from outside. Switch on the power and wait about 3 days, and ice will start forming around the edges.
* SWITCH OFF AND UNPLUG BEFORE ANY ACTIVITY*
Then you can jump in! Any more ice and your shoulders won't fit. If you forget to switch it off, say during a week overseas, you will be greeted by an entire block of solid ice.
Throw a pool thermometer in for good measure.
[Update: 14 Dec 2020] Overhaul/Maintenance
Hundreds of dips later, the walls of the tub were starting to get soft. I found that these were due to micro-holes/punctures that allowed the water to seep in and get absorbed into the insulating foam. An overhaul was required so I figured it was a good time to cover over the exposed metal. After a lot of research, I settled upon the U-pol Raptor truckbed liner in white colour. This requires a mix with the hardener in order to activate the paint
How do you clean it?
You will not believe the amount of gunk on your body that you carry around with you. Skin flakes, hair and many unknown bits will fall into the tub and there's only so many times you'd want to completely empty and refill the tub. I've decided to treat mine like a swimming pool and get this Intax pool filter to suck up all the human debris weekly for a few hours. The water goes from murky to Crystal Clear, as the model suggests. You will still have to clean the filter by flushing it and knocking the dirt out.
Finally to kill all the germs and get that "New Pool Smell", I got a tub of chlorine powder. For this size only one tablespoon of powder is needed. You have to put it in some water to dilute first until all the hard bits dissolve before pouring the cloudy mixture into the tub. Give it a day while filtering and the tub will be disinfected and smell wonderful. Be careful though, when you open the powder container, the concentrated chlorine smell is incredibly strong and will give you a shock! I hold my breath every time I peel the lid open to get a scoop of it out.
That's all there is to it, enjoy your ice tub!