When you have already decided which brand of LED grow lights to buy, there is one more question you need to consider, what size grow lights should you buy? If you choose a light fixture that doesn't fit your grow tent, you won't get a great growing experience. Read this article to choose the right size LED grow light for your planting!

Wattage is the traditional way to calculate the number of grow lights in a grow tent. It is often assumed that the wattage of the grow light determines the efficiency of the light, but it is not. From a physical point of view, power and efficiency are two different concepts. You can use wattage to get a rough idea of LED grow light coverage.

The light intensity (high light or low light) needs of the plant and the total area of the growing space determine how many LED watts (W).

1.Growing space

The first step in thinking about how many lights you need is to calculate your growing space. Once you have determined the growing space and the number of plants you intend to grow, you can calculate how many lights you need to cover the entire area. The amount of lighting required per square foot also depends on the type of plants you plan to grow, as some plants require more or less lighting. In theory, 1 square foot of grow space requires 32 watt LED grow lights.

Example: I have a growing tent that is 3 feet long and 3 feet wide. This gives me 9 (3ft x 3ft) square feet of growing space, then multiply 9 by 32w to get 288w. So I need an LED grow light with at least 288w.

Then determine the area you want to cover. For example, if your grow tent is 5X5, and your plant canopy area is 4X4, then the number of LED watts you need is (4X4) X32=512 watts. Usually LED merchants will also recommend the coverage area of LED lights. If you have plans to grow more, you will need to buy multiple lights hanging side by side to cover each plant to get the same amount of light, using LED grow lights with a daisy chain feature will save you even more time!

2.What to grow

What are you growing? Generally speaking, the light requirements of flowering and vegetables are not the same. Vegetables require less light than flowering, so lamps with lower power will be more suitable for vegetable growth.

For plants that require high light, LEDs require 30 to 40 true watts to cover 1 square foot of space.

For plants that require low light, it will take about 15 to 20 real watts to cover 1 square foot of space.

Some common plants with high light: Tomatoes, peppers, peas, cucumbers, okra, hemp, citrus, etc.

Some common low-light plants: Herbs, leafy greens (lettuce, kale), Lucky Bamboo, Calathea Peacock, Carrots, etc.

Here's a quick and easy tip for distinguishing high-light plants from low-light plants: high light plants are usually flowering and/or fruiting plants, and low light plants are non-flowering plants.

3.Plant Growth Stages

Plants have different requirements for light intensity in different periods. Most plants don't need much light in the seedling stage, and as the plant grows, so does the need for light. Plants in the vegetative stage need about half as much light as they need to bloom. If your plants spend their entire lives in this tent, then you'd better buy a dimmable LED light. The dimming function of Bestva LED grow light saves you a lot of trouble and meets the needs of plants for light in different growth periods.