How Far From Plants? Keep 12+ inches (30cm) away from tops of plants
Digital ballasts cost a bit more than a magnetic ballast, yet have big advantages. A digital ballast runs cooler, uses less electricity and produces a higher light intensity. If you like taking pictures of your plants, a magnetic ballast will make dark lines all over your photos. In addition to no lines in pics, digital ballasts are compatible with more types of bulbs, while a magnetic ballast needs special magnetic ballast compatible bulbs and will burn out the wrong type of bulb.
Choose the right size MH/HPS light for your space
Notes: Nearly all 150W MH/HPS have a “Built-In Ballast,” which means everything is actually attached together and you just plug the light directly into the wall. A 150W does not get very hot compared to all other HID grow lights, and many growers may not need any kind of exhaust system with a 150W.
Wings are basically just a reflector with a built in spot for the bulb to connect. Wings don’t have any built-in cooling options and can tend to cause hot spots on the tops of the plants. Wings are usually the cheapest option and often have shoddy construction. Plus the edges can be sharp, not something you want at face level!
For longer lasting bulbs….
Digital vs Magnetic Ballasts – Digital ballasts cost a bit more than a magnetic ballast, yet a digital ballast runs cooler, uses less electricity, tend to produce higher light intensity, and will save you money in the long run.
Next, use some ducting to trace a round, duct-sized hole on the foam/plastic. Note: Cut out the duct-sized hole in the foam/corrugated plastic near the top of where it will be mounted. Remember, heat rises, so having the exhuast exit near the top is much more efficient.
First of all, you should know that an HID (High Intensity Discharge) Grow Light System isn’t the right choice for all cannabis growers. Just like any other cannabis grow lights, MH/HPS grow lights have pros and cons.
Now that you know exactly how to get started…
Compared with HPS lamps, MH lights produce a blue-hued light. Although MH bulbs naturally produce fewer lumens than their HPS counterparts, they hit the spectrum needed for bushy, short vegetative growth.
Lighting size is always a calculation based on many variables, all of which differ from one grower to the next. Determining the number of plants (or canopy size) per metal halide isn’t a simple formula.
As a grower, you will adhere to one of two lighting programs in indoor cannabis cultivation: LED or HID. High-intensity discharge lighting (HID) is the traditional (and arguably most intense) option. Under this umbrella are two types: High-Pressure Sodium (HPS) and Metal Halide (MH).
Metal Halide Light Spectrum is Ideal for Veg
In the grand scheme of your grow room budget, HIDs offer the most affordable upfront costs. However, they do produce a lot of heat, and when it comes to energy consumption, they are not as cost-effective as LEDs (find out more on whether or not LEDS are worth the cost).
Metal halide is a type of HID bulb, producing light from an electrical arc sent through a mixture of gases: vaporized mercury and metal halides. Metal halide fixtures include three parts: a ballast, bulbs, and a reflector.
Like all HID bulbs, metal halide bulbs have a limited lifespan (at least compared with LED fixtures). Generally speaking, you can expect to get upwards of 20,000 hours of output, but there is a steep degradation.
Metal Halide Grow Lights For Cannabis
Beyond the affordability and intensity, what makes MH a preferred indoor grow light for cannabis cultivation? MH bulbs are perfect for the veg room.
In terms of lifespan and ongoing energy costs, they are more expensive than LEDs. Even compared with HPS lighting, they consume substantially more energy.