Choosing Lights for Growing Cannabis

Lights are the most essential part of your grow, and because of the whole techie aspect, they can be super daunting! There are many options available to today’s energy-conscious grower. In GrowCast Episode 7 David shares his tips and tricks about all things illuminated.

In GrowCast Episode 7:

• LED lights and how they work for growing cannabis

• Traditional Metal Halide and High Pressure Sodium Lights

• CFL light option

• An update on my grow

Show Notes

Here is the light formula mentioned in the show. It will help you decide how much light you need in your grow space.

To determine how many lumens per square foot you have:

Find out the square footage of your space
Width x Depth = Square feet. Divide the lumens available by your square footage
This will give you lumens per square foot

Example: Say your space is 3 feet deep by 4 feet wide, 12 square feet. The total lumens available from your light(s) is 45000 lumens. 45000/12 = 3750 lumens per square foot.

To determine how much light you need in watts?

The general rule of thumb for providing light for an area is a minimum of 30 watts per square foot but 50+ watts per square foot is ideal. Determine the proper lighting for your area by using this formula:

50 watts (or the total watts you are using) x (your square footage)

Example: You have an area of 10 sq. ft. – 50w x 10 s.f. = 500watts/sq.ft minimum or 50 watts x 10 s.f. = 500 watts/sq. ft. (optimal).