What is BTU and what is a BTU rating? Simply put, BTU stands for British Thermal Units and is the amount of heat necessary to raise the temperature of 1 pound of water one degree Fahrenheit.
How is this important to growing cannabis you ask? Liquid Jade talks all about BTU in the video below. He has two grow tents inside his grow room - one 4x4 grow tent with 1 plant and one 4x8 grow tent with 10 plants. Strains he is growing consist of Aurora Indica and Bubblicious by Nirvana seeds. He not only talks about BTU ratings for traditional LED grow lights but also compares with Spectrum King LED grow lights.
Also in his video he teaches how to "top" cannabis plants.
Check out his video here: