Introduction

This is the first blog for my Experimenting with Extreme Environment challenge entry and also my first blog for any challenge overall.

My project will focus on helping me increase the useful life of the new equipment I will be installing at home, while also trying to avoid any breakdowns.

In the last two months, I have been building a swimming pool at home. This swimming pool will be equipped with saline electrolysis equipment. This qualifies as an extreme environment, as the equipment should stand up to different factors like immersion, UV radiation, salt and chlorine. 

The aim of this project is to couple the provided materials with an immersible temperature sensor I already own.

Anyway, before giving more insights about the project, let's properly explain what saline electrolysis is. 

Saline electrolysis explained 

In order to have clean water for a swimming pool, a process of disinfection is necessary. The most widely used method is the application of chlorine tablets. However, these tablets also have isocyanuric acid, which is not good above a certain amount. This acid doesn't disappear unless you empty the pool. 

Nowadays, a lot of residential swimming pools use saline electrolysis for water disinfection. This is just another way to generate chlorine without adding isocyanuric acid.

The salt chlorinator is a bleach factory. First of all we dissolve common salt in the pool. The water with the salt flows through an electrode where sodium (Na) and chlorine gas (Cl₂) are generated. Part of this gas recombines with water generating hypoclorous acid (HOCl) which is the one used for water disinfectation. 

The use of a saline electrolysis machine usually increases the pH of the water, so it is usually coupled with another machine that measures the pH and lowers it to a desired value (usually about 7.8). Moreover, we can also measure the ORP value so we only generate chlorine when it is really needed. 

A scheme of the saline electrolysis process is depicted in Figure 1.

Figure 1. Saline electrolysis scheme (Source: https://upload.wikimedia.org/wikipedia/commons/6/6a/DownsCellSchematicColor.png) 

Aim of the project

As with any other disinfection method, saline electrolysis has both advantages and disadvantages. A critical parameter that is not usually explained is water temperature, as this kind of equipment should not work at temperatures below 13–16 °C. 

I would like to measure the temperature of the water, display it on the included display, and also create a website to check the current temperature and previous ones, which will be represented graphically. 

In the future, I could also start/stop the saline electrolysis equipment automatically with the temperature measurement. 

The next blogs will feature an unboxing of the received materials and the prototype building process.