Light intensity is measured by PPFD (photosynthetic photon flux density), which is the amount of light that reaches a certain area per second. Different plants have different PPFD requirements depending on their species and growth stage. For example, low-light plants such as ferns and prayer plants need around 100 PPFD, while high-light plants such as tomatoes and peppers need around 800 PPFD. To adjust the light intensity for your plants, you can use one or more of these methods: Change the distance between your light and your plants. As mentioned earlier, moving your LED closer or further away from your plants can increase or decrease the light intensity accordingly. Change the wattage or spectrum of your light. Some LED lights allow you to change the wattage or spectrum of the light by using a controller or a switch. This way, you can adjust the amount and quality of light that your plants receive. Change the duration or cycle of your light. You can also adjust the light intensity by changing how long or how often you turn on your LED. For example, you can increase the light intensity by extending the photoperiod (the number of hours of light per day) or decrease the light intensity by shortening the photoperiod.