Now in our world here are many global problems that need to be addressed immediately. They concern not only nature, but also man himself. We set out to understand how you can still use the sun in homes, except for lighting. To do this, we chose a small settlement on the water in Nigeria. Makoko slums are located on the edge of the Atlantic Ocean, in close proximity to the modern buildings of Lagos, the largest city in Nigeria and the main commercial and industrial center. Thousands of people live in these slums, stretching along the coastline for several kilometers, in fragile wooden huts. For many decades, residents in Makoko have not had access to infrastructure, including clean drinking water, electricity, and waste collection, which threatened the environmental crisis. All waste and sewage are discharged directly into the water. The only way to get drinking water is to buy it from sellers, as the government does not provide free water to residents of Makoko. Having studied a lot of information, we wanted to help people make their living conditions a little better, because there are a lot of such settlements in the world. Our idea is to purify water using light, illuminate the main street and additional light in residential buildings. We tried to take into account all possible difficulties in implementation. 1. In the central part of the settlement, we set up a tower building on which a round-shaped tank was installed. In the water there are special nets - filters for purifying water from debris. From the bay, water enters the tank, where it is cleaned, thanks to the flocculation process. To illuminate the ball, we used simple fluorescent stones that illuminate the water. The light from the ball creates scattering light on the streets of the settlement. 2. Next, it was necessary to deliver water to the houses, so we decided to run hoses from the ball, in which there were also small pebbles, for additional filtering and lighting. 3. Water from the hoses flows into small plastic volumes installed in the roofs of buildings. There is another process of water filtration - SODIS. The volume of water located is located on the south side of the roof, and due to this, sunlight has a better effect on contaminated water due to the synergy of the three mechanisms of radiation. 4. And the last, since the volume is inserted into the roof itself, it carries the function of a window, but thanks to the plastic containers in the house there is no overheating, but on the contrary, cooling and a beautiful pattern inside the house are created. We hope that this concept will help people pay attention not only to the problem of pollution of the Earth, but also to understand that some people do not even have drinking water. Our idea does not purify water before drinking it, but it makes it cleaner for domestic needs and swimming.