I have one next to my bed. Bought a used one that it roughly 20 years old ^^<p>I plan to replace the temperature sensor + controller with some 1 wire ones and use a raspberry pie to control the heater.<p>Some time ago I build a underwater speaker but the first experimental design is kind of quiet. It is unbelievable how expansive commercial once are. They are in fact just a speaker which use the plastic housing as membrane. Maybe I should print a housing.<p>As a addition I added a oxygen compressor to boost the oxygen level inside the tank. It is much more comfortable as the quite high humidity inside the tank is not that pleasant.<p>If you build a tank from scratch, I would say ~1500 € in material, depends how much you want to hunt for heap parts.<p>Nice things not many know:<p>you can sleep quite good in the tank. It&#x27;s different form of sleep, but very relaxing. You drift more between the sleep world (DMT) and awake world (Serotonin). Very lucid dreams, sometimes multiple a day.<p>No, you don&#x27;t rotate as those are reactions to pressures which you simply don&#x27;t have. If you turn, you will awake. Usually those tanks are filled with bittersalt, which is very, very bitter and burns like hell ^^<p>I rotated once, because I had a very lucid dream about drowning and panicked after waking up. Funny thing, it was then when I actually rotated and drank a good sip of water ^^<p>You should not overdo it, as it may affect your ability to sleep in a normal bed.<p>If you spend longer time in the tank &gt;9h-12h, depends on the person, you get hallucinations from sensor deprivation. A very interesting way to observe internal states without altering them first. But of course, it&#x27;s only nice if you know that you can open the door anytime you want. Once you spend some time in it, you understand why this can be abused for torture as well :(