How to extract drinking water from sea water. Part 1: The thought process.

Most of us are aware that the ocean is full of water. And, some of us, Homer not included, know that the oceans' water cannot simply be consumed in the state in which we find it in nature. Doing so would be a death sentence. 
I find it interesting that when swimming at the beach, we rarely take the time to think about the fact that we are floating in a liquid that could kill us if too much of it is consumed. But there we have it. Despite this simple truth, we can freely go to the beach and swim in a liquid that could lead to our own demise. It just goes to prove the old adage that ignorance is indeed bliss. 
I bring this simple truth to the surface for one excellent reason. At times, water can be incredibly scarce. And to those who have been unlucky enough to have been trapped at sea, ocean water starts to look very tempting once thirst takes hold. Therefore, understanding how to extract drinking water from ocean water is an excellent process worthy of comprehension. The good news for you is that removing drinking water from the ocean is not as hard as you think. In fact, once you understand the basics, it is something you will never forget. Furthermore, knowing how to complete this process may inspire you to come up with inventive ways of extracting the drinking water yourself. Basically, when it comes to learning water distillation, the rabbit hole tends to quickly become wonderous.
For example, one such wondrous rabbit hole appeared just the other day. I dove into it headfirst, keen to see where it would take me.
Often I find myself reflecting on the many rabbit holes I have ventured into. One of the most exciting aspects of a sound rabbit hole is how I discover them in the first place. Sometimes the entrance to a rabbit hole can be obscured by the craziest stuff. Interestingly, this rabbit hole story starts with seeds and mice.
For years I have been learning how to grow my own vegetables. Participating in agricultural activity is one thing. Mastering it is an entirely separate concern. Let us just agree that I am far from ultimately perfecting this. I have found that each season brings new challenges, and there is always something new to learn. When it comes to growing your own vegetables, concerns such as weed, space and time management are some examples of the lessons that are waiting to be taught. However, it's the lessons that have teeth that tend to bite though; they also have a way of sneaking up on you while you're not looking.
In all honesty, pest management was something I should have been better prepared for. The topic was never entirely overlooked. Some thought has been given to pest management in the past. Sure, keeping my dogs out of the garden has always been an issue. I had already solved this by completely isolating the grow zone. But mice don't care for fences. This particular pest issue began at the time of sowing. I would plant the seeds in the afternoon in their own unique little punnets so I could better support the first stages of their life cycle. The following day I would go about my life, assuming that my seedlings were perfectly safe. As far as I was concerned, they should have been! Then, after work had finished, I would race home to see the seedlings progress.
Keeping the seedlings moist was essential; watering quickly became a part of my daily routine. I also came to learn not to consider it a chore. After all, I was keen to see the plants. I eagerly waited for the day that the seedlings would emerge. Unfortunately, when the time had come to water the plants, I often found the pest issue would reveal itself. Instead of seeing my seedlings as I had left them, all that remained was a little hole where the seed had been planted and tiny digging marks. Unwittingly, the seeds had become mouse fodder. Mice?! I wasn't even aware that we had a mouse problem! Of course, I was now that all of my seeds had been dug up and eaten by Disney's most adorable! This could not be allowed to continue! I needed a quick solution. When it comes to raising seedlings, time is of the essence. But how was I going to fix this problem?
Embarrassingly, I must admit that it wasn't the first time I had seen this issue either. I have tried to plant my seeds directly into the ground during previous seed raising attempts. Again, I would return to find that the seeds had also been removed. It felt like a cruel joke. Often, I found myself wondering if someone was messing with me. Maybe it was the neighbour? Yes! That's it, it was the neighbour, and he was jealous of my agriculture skills! Of course, it wasn't my neighbour, but I couldn't be sure at first. The other problem with planting seeds directly into the ground was birds. These winged creatures of the air were notorious for taking seeds from the ground. And in any other circumstance, I would have blamed the aviation animals for this particular theft of seeds. Still, the evidence was on the soil, and birds don't dig, leaving little mounds behind where the seeds once were! Mice it was. 
So, to fix this problem, I simply purchased a clear plastic container large enough to put the seed punnets into. Easy done, right? The plan was to water the punnets and then seal them into the container with a clear lid. Air could still move freely in and out of the container. The cover, after all, was not a sealed fit. But, it was closed enough to keep the rodents out while still allowing the air and carbon dioxide to move freely. So, there you have it. Seedlings in and rodents out. The transparent make of the container still allowed the sunlight to enter the container, so I had the light issue sorted. 
One of the unforeseen outcomes of this transparent container experiment I soon discovered was that any water watered onto the seedlings was to become trapped in the box. In effect, I created a solar condensation cell. As it was to turn out, this was to become a crucial step in understanding water desalination. See, from mice and seeds to water desalination in less than seven hundred words. Damn, I rave on sometimes...
The first step of this desalination process was completed during the warm daylight hours. This warmth would lead to the evaporation of the water I had used to water the seedlings. Just like that, I had moisture-laden air. The second step was completed after the sun had set. The night air was cool, which led the moisture-rich air in the container to re-condense along the sides and lid of the container. This leads to the moisture running down the sides and ultimately filling the bottom of the container with liquid water. 
After a couple of days of observing this condensation cell in action, I thought of a project I had been planning on completing ever since moving closer to the coast. The project was simple enough. 
Take a bucket of water from the ocean and extract both the salt and the drinking water from it. I desired to document the weight of the water before starting the process and the quantity in litres. Then, once the process had been completed, I simply had to weigh and measure the outcomes. If done correctly, I would have an honest answer about how much drinking water and salt could be extracted from one litre of ocean water. I would also document the amount of energy required to complete the process. The amount of energy necessary to complete the process was an integral part of the experiment. I soon discovered that there are many ways to extract drinking water from ocean water. Some are far quicker and more energy-intensive than others. These often require more moving parts, and from what I have learned about any system of any size, the more moving parts a system has, the more things tend to go wrong with it in the long run.
For my first attempt I decided to use an air still to complete the process. Please see the video below.
A follow up article will be written in time detailing the complete process.