WATER SYSTEMS FOR HYDROPONICS AND GARDENING

Should I use a UV lamp in my irrigation system?  
Published 17 April, 2020

All those chlorine-free waters (wells, ditches, reservoirs, etc …) are susceptible to accumulating unwanted substances for irrigation: viruses, bacteria, herbicides, pesticides… Therefore, one of the questions that most concerns growers who use these types of water, it is whether they should use a UV lamp to sterilize the water, or not.

When we grow, we have several obvious reasons to maintain a pathogen and unwanted bacteria free setup. And the best way to do this is to start with a purified base water, using a Reverse Osmosis System. But there are some cases where it is necessary to add a UV lamp as a sterilizer.

In the case of using a Reverse Osmosis system or a Filtration System, it is necessary to install the UV lamp in the irrigation circuit, before these, to kill 99.99% of viruses and bacteria, thus sterilizing water. Furthermore, by installing the UV lamp before our water treatment system, we will lengthen and protect the life of the systems filters.

Ultraviolet radiation

Ultraviolet radiation or UV radiation is an electromagnetic radiation whose wavelength is approximately between 10 nm and 400 nm. Its name comes from the fact that its range starts from shorter wavelengths than what humans identify as the violet color. But this light, or wavelength, is invisible to the human eye as it is above the visible spectrum. This radiation is an integral part of the sun’s rays and produces several health effects because is between an ionizing and non-ionizing radiation.

Types of UV radiation

There are 3 types of ultraviolet radiation, according to their wavelength:

UVA: UVA radiation is the least harmful and the one that reaches Earth the most (95%), but overexposure is also harmful. Almost all UVA rays pass through the ozone layer. It is responsible for the immediate tanning of the skin. In the long term it also favors skin aging and the development of skin cancer. It is between 320 and 400 nm.

UVB: It is biologically very active but the ozone layer absorbs most of the UVB rays from the sun. However, the current deterioration of the layer increases the threat of this type of radiation. As short-term effects, it is responsible for burns and delayed tanning. In the long term, it favors skin aging and the development of skin cancer. It is between 290 and 320 nm.

UVC: It is the most harmful due to its great energy. Fortunately, oxygen and ozone in the stratosphere absorb all UVC rays, so they never reach Earth’s surface. It is between 100 and 290 nanometers.

How does a UV sterilizing lamp work?

The key factor for effective operation of a UV sterilizing lamp lies in the wavelength of the light it emits: UV-C light. With a short and powerful wavelength, it destroys nucleic acids in the DNA of a pathogen. Eliminating their ability to infect, reproduce, and perform vital cellular functions, making them harmless.

Its use is recommended in cases of using accumulation water tanks. Especially if they are exposed to the sun and the water remains stagnant for an amount of time. Even if you have used previously treated tap water, if that water will also remain stagnant for an extended period of time, there is a very high probability that unwanted pathogens will proliferate again. In both cases, the only way to ensure complete sterilization is to install the UV lamp after the accumulated water has been deposited, before the water enters the crop irrigation circuit.

For all the cases in which it is watered using a chlorine-free water, coming from wells, ditches, reservoirs or similar, GrowMax Water offers different Kits of UV sterilizing lamps: The UV Lamp Kit 4 LPM (with a flow of 4 L/min) and the UV Lamp Kit 22 LPM (with a flow of 22 L/min). Which include transformer, fittings and wall mount clips. Everything ready to install and use.