These are high-intensity discharge lights. They emit light when an electrical current is passed through a tube filled with the inert gas xenon and flowering of gas that is a mix of sodium and mercury vapor. The results are light that is strong in the orange/red spectrum at around 2200K which is the most ideal for healthy development of the Marijuana plant throughout all the stages of growth from Seedling all the way to the budding and flowering stage.

The marijuana plant requires three spectrums of light for its budding and flowering stages. These include the oranges, yellows, and reds. The three are found in quantities of 590-630,570-590 and 630-750 (nm) respectively.

 HPS Grow Lights

Advantages of using HPS lights include:

  • The light produced is approximately 140 lumens per Watt which happens to be a lot of light for your plants.
  • The light emitted is in the ideal spectrum for your budding and flowering plants.
  • The HPS Lights are easily available an example being the orange tinted lighting used in car parks.

There are also disadvantages associated with the HPS lights, these include:

  • The lights produce a lot of heat; HPS grow lights generate a lot of heat. It is essential to ensure that space is well ventilated in this case.
  • Heat generated from the lights means that the lights have to be placed at a distance from the plant’s tips. This means that the plant will not get the much-required light if it the light is placed further
  • The lights require ballast for regulation of the flow of electricity to the bulb. They are likely to use between 50-150 watts of power which increases the cost of power.
  • The HPS bulbs have a short span of life.  It is therefore recommended to change them after about three cycles of growing regardless of what the manufacturers’ has given as a life expectancy


Ensuring that your grow area is kept cool

We have already established that the HPS lights operate at high temperatures. It is therefore essential to remove the unnecessary heat from the system especially if you grow in a confined space.

The best temperature for growing marijuana indoors ranges between 70oF and 75oF during the day and 60oF to 70oF during the night. It is important as a grower to ensure that this is observed.

It is important for a grower to maximize on the actual light available during the day. The lights can then be used at night to generate heat because of the cold and darkness.

It is important to put the fans beneath the lights and above the canopy. Air circulation helps in strengthening branches, stems and ensuring movement of air that will ensure fresh air loaded with CO2 is available for the plants.

HPS grow lights are fitted into cool tubes. This remains to be the best way to deal with the heat generated by the lights.  It is therefore recommended that one uses the cool tubes especially if the bulbs use more than 600W.