It is important for you to filter the water that gets into your rainwater tank in order to make that water safe for use. This article discusses some of the options that you can consider in case you want to add a filtration system to the water tank that is storing rainwater on your property.
The most basic way to filter water is passing that water through a mesh that is made from various materials, such as stainless steel or polyethylene. The mesh should be fine enough to trap most of the litter and other solid materials that may be carried by the water on its way into the tank. This filtration system is very affordable. However, its major limitation is that it is only effective against particles that are larger than the mesh size. Finer particles, such as small sand particles and microbial/chemical contaminants will still find their way into the tank.
You could also consider installing a first-flush diverter on your water tank. Such a device directs the first onrush of water away from the entry of the tank before letting the subsequent water to flow into the tank. The assumption behind the working of the diverter is that most contaminants, such as leaf litter and dust, will be washed off the roof by the initial water that runs down the roof. The subsequent water will then find a clean roof. It is this cleaner water that the diverter allows into the tank. Some models of the diverter allow you to set how long you want the water to flow away from the tank. First-flush diverters also don't address chemical or biological contaminants.
Activated Charcoal Filters
Another filtration system that you may use contains activated charcoal. This filtration system is placed at the point where water gets into the tank. The activated charcoal attracts and absorbs many of the contaminants, such as microbes, fine particulates and some chemical pollutants. However, the efficiency of this system may be reduced in case large volumes of water are getting into the tank at the same time. Some of the water will pass through the filtration system without being adequately filtered.
Chemical Filtration Systems
Chemical and microbial contaminants can be dealt with effectively by the use of chemical filtration systems that are installed inside the tank. For example, you can acquire a chemical dispenser to release measured doses of chlorine into the water in order to control biological contaminants in the water. However, care must be taken to avoid accidentally overdosing the water since the chemicals can be harmful to humans and animals.