This 101 guide is limited to suggestions specific to your lamps. You’ll find growing with LED lamps requires a departure in thought from using high pressure sodium or other HID technology – a departure that you will benefit from when you pay your electricity bill.
Whether you are swapping out your previous lamp technology or starting a new operation, investing in the right set of environmental circumstances is worth the effort. Typically your normal temperature in a grow room running HID lighting is somewhere between 70 and 74 degrees causing major HVAC installations and high energy bills in the summer. Due to a lack of internal heat build within the plant when growing under LEDs, I’ve found that cannabis has the best results when grown with ambient room temperatures between 80 and 82 degrees. I do want to point out that this does not mean that you cannot grow in temperatures under 80 degrees but results will vary. This internal temperature within the plant also refers to points 2 and 3 below.
I personally like a lower humidity when flowering, specifically during the last 2 weeks – this is when the plant is more susceptible to molds such as powdery mildew and botrytis. Although maintaining relative humidity is very important in your environment, air circulation is key as well. I prefer three main levels of fan control. I refer to these levels as below canopy, above canopy, and ceiling/upper. Creating vortex effect throughout the room with fans is my preferred method of choice of fan placement in those zones. Misconceptions of canopy density using LEDs are being broken down with simple experience.
The closer the light is the smaller your footprint. I suggest 18″ with slight side canopy manipulation such as super cropping or trellising. This allows for the light to have nice canopy penetration. Light bleaching can occur on certain strains but usually happens when the plant is closer than 10 inches. The ability to have the plants growing that close to light refers back to point 1. Although not ideal, the plant can survive much closer to LED compared to HPS. Canopy density is very important to a quality yield. Each diode has its own individual optics based lens which allows for blended wavelength uniformity as well as light penetration deep within the canopy.
You can download Heliospectra’s complete guide on growing marijuana here