If you’re planning to buy the best LED grow light for your plants and you need to make sure it’s the right size for your garden, you’ve come to the right place. In this article Spider Farmer will teach you the most basic ways to calculate the number of lights you need specifically. 

Know the size of the planting area Many people tend to overlook the size of this area of the plant they are growing when considering what size grow light to buy. 

1, Measure the overall dimensions of the planting area: Of course, the most basic thing is to measure the size of the entire planting area, including the length and width. Only with this data can the most suitable number of plant lights be calculated. You need to be careful when measuring because this is the most important data. 

2, Measure your canopy’s length and width. The canopy is the part of the plant that absorbs light. It is what you’ll have to measure when considering what grow lights to choose. 

3, Measure your canopy’s depth Don’t overlook the depth of the canopy. You need a light strong enough to penetrate deep into your plants. It’s not enough to just cover the top of it. According to the above factors, we provide you with the number of plants that can be accommodated in the fixed planting area size. You can use it as a reference and then compare the data provided by the grow light manufacturer. 

Planting Area Size            Recommended of Plants in Veg                  Recommended of Plants in Flower  

70x70cm                                           Up to 4                                                                 Up to 2 

90x90cm                                           Up to 9                                                                 Up to 5 

70x140cm                                         Up to 8                                                                 Up to 5 

120x120cm                                       Up to 16                                                               Up to 9 

150x150cm                                       Up to 25                                                               Up to 12 

Determined by the lumens/PAR required by the plant 

PAR is essentially a measurement of light emission within the photosynthetic range of 400-700nm. This represents the area of light that plants use for photosynthesis, or to grow. PAR is measured by the amount of micro moles of light per square meter per second. Plants need visible light to grow, and while household lights are measured in watts and lumens, understanding PAR is the best way to understand how much light plants need to grow. 

Generally speaking, regular LED grow lights will provide customers with PAR map, you can check it yourself before purchasing. But different plants require different PARs, so you need to research how much your particular plant needs for optimal growth and production. Once you know this, you can determine how many lights are needed to provide that much PAR. 

Spider Farmer Makes Your Choice Easier I believe that after reading the above introduction, you have a general understanding of how to choose lights according to the size of the planting area and the PAR required by your plants. In order to facilitate customers’ selection, Spider Farmer recommend the corresponding suitable planting area size for you in the introduction of each light. If you have any questions in the process of choosing a grow light, please be free to ask us.