One question that seems to come up over and over is how many LED watts per square foot? After looking into this question, I have come to the conclusion that there is no clear cut answer unless you are willing to invest a lot of time studying your particular grow and a few hundred dollars on a PAR meter. However, to really get to the bottom of this question, it ultimately depends on a multitude of factors. So, in writing this short article, I decided I am not going to go into detail. Therefore, I will do my best to provide a quick and reliable short answer that is easy to understand. My goal is to give you a general understanding and point you in the right direction.

Google Recommends 32 LED Watts Per Square Foot

If you are reading this short article, you more than likely did a google search. I also did a google search. I noticed Google recommends 32 LED watts per square foot. But is this number correct? In my opinion, it does not tell the full story. When considering how many LED watts per square foot, you must consider a few factors. These factors mostly include your light and it’s performance. But through my research, I discovered one underlining theme… you get what you pay for.

First, I would like to start with LED light efficiency. Most LED light manufactures do not list efficiency in their buying guides. They do this because it probably is not very good. For instance, let’s say you purchased a generic 100 watt LED with 30-35 percent efficiency. That would mean your grow space would only receive 30-35 usable watts. That’s a lot of waste!

Another point to consider is they type of LED. If you are using an older model that you purchased years ago or a cheap generic brand, then I strongly suggest having more than Google’s 32 LED watts per sq ft recommendation. As I alluded to earlier, you get what you pay for. The best LED’s are probably twice as efficient as the worst. If you are looking to purchase a new LED light, I would recommend sticking with name brands. Look for name’s like COB or Cree when purchasing.

Quick Points

• Your plants light requirements will vary based on its growth stage. Seedlings require the least amount of light, whereas flowering plants require a lot more light. (Seedlings<Veg<Flower<CO2 Supplementation)
• No artificial light can match the power of our Sun. Your plant will take all the light you can give it. If you add more light, make sure you keep the heat down. Good ventilation is crucial for success!

Conclusion

Lastly, if you have any questions please post them in the comment section. I also urge you to share in the comment section if you have experience or expertise in this area. If you are interested in learning even more about growing cannabis, please check some of my other articles! Here are a few of my most recent posts: 

• The Cannabis Growing Season – Southern California
• Is a Grow Tent Necessary
• Trichomes When to Harvest
• Cannabis Water Filter
• Organic Fertilizers for Cannabis
• Cannabis Pot Size Guide