Grow Light Basics, Part 2: Types of Grow Fixtures and Timers
In part one, we discussed the different types of lights and their respective coverage. In this part, we’ll look at the different types of fixtures more closely, helping you choose the right reflector for your growing needs. Once you’ve chosen your bulbs, you have to choose a fixture to give you maximum reflectivity and coverage. There are about four types of grow light fixtures to choose from: high bays, strips, open air HID, and enclosed HID.
Imagine lighting fixtures in a warehouse. The high bays used for indoor growing are just modified versions of those warehouse fixtures and come in HID, CFL, and linear fluorescent versions. The HID and CFL high bays are great for starter grows, and are only suitable for growing a few plants due to small coverage areas. On the other hand, linear fluorescent high bays are an ideal choice for T5 fluorescent grow lights, as they have larger coverage areas and operate two to eight individual bulbs.
Linear fluorescent strips are only suitable for growing compact rows of vegetables or herbs, as they only operate one or two lamps.
Open Air HID
These types of fixtures are the most common type of grow light because they produce high lumens, have great coverage, and provide sufficient cooling. Open air HIDs include wing fixtures and parabolic fixtures.
Similar to open air HID fixtures, enclosed HID fixtures include air cooled and “cool tube” fixtures. However, these types of HID fixtures offer two distinct advantages over the open air HID fixtures. One, the bulb is protected by a tempered glass lens, which protects your plants and grow area from glass in the event of a bulb malfunction or thermal shock from overspray of water or other liquids. Two, the fixture offers better cooling. Both types of the enclosed fixtures feature flanges on either end for external cooling, allowing you to send a constant stream of air past the bulbs, therefore keeping both the bulb and your plants at a safe temperature.
Types of Timers
Now that we’ve covered the types of grow light fixtures, we’ll discuss the different types of timers and their importance in your grow project.
Just like you and me, plants require sleep. Generally, plants need 15 to 18 hours of light a day during the growth phase and 10 to 12 hours of light during the flowering stage. For the remainder of the time, your lights should be off. You can accomplish your plants’ lighting needs in a few ways: by manually turning your lights on and off (not really recommended) or by utilizing a simple plug-in timer. Manually turning your lights on and off isn’t recommended for one reason: you may forget to turn them on, or you may forget to turn them off, both being detrimental to your plants’ health. The answer to you plants’ lighting needs is a plug-in timer, offered either in digital or analog format.
Analog timers are generally cheaper and somewhat easier to use than digital timers. These types of timers have a dial that turns throughout a 24-hour cycle and trippers that turn the lights on and off. You place one tripper at the time you want your lights on, and another when you want your lights off. When the timer hits these trippers, the lights either turn on or off. However, most types of analog timers lose time when there is a power outage.
Digital timers are definitely the recommended type of timer for your grow light project. These timers work pretty much the same way as analog timers, but offer a few key advantages over the analog timers. For one, they solve the problem of losing time when there is a power outage. These timers have battery backups that remember the time and set points should there be a power outage. Additionally, many of these timers are self-adjusting, resetting themselves for daylight savings time and even calculating sunrise and sunset times based on the time of year.