Serious indoor marijuana growers almost exclusively rely on hydroponics high-intensity discharge (HID) lights for their full-size marijuana gardens.
But marijuana growers are concerned about quality and performance issues with hydroponics ballasts and bulbs, so our BigBudsMag.com cannabis grower team put together this guide to HID bulbs so you get the most and best light for every dollar you spend on HID bulbs and on the electricity to power them.
HID bulbs are fascinating to look at and understand. They produce light when electricity is transferred in a sealed chamber (the arc tube) between two electrodes surrounded by pressurized gases and metal salts.
In hydroponics bulbs for marijuana growers, the relevant chemistry is that one type of bulbs includes metal halide (MH) in its sealed chamber, and the other type uses high pressure sodium (HPS).
The chemists and engineers who design HID bulbs are like technological chefs working with a recipe consisting of electricity, gases, metal salts, high-pressure, and electrical components such as tungsten-coated electrodes.
Many of these ingredients (such as mercury) are toxic or otherwise dangerous. The degree to which they’re selected and combined determines the quality of the bulb.
The type of light wavelengths and intensity you get from HID bulbs is controlled by what the chemists and engineers did to create the bulb design, how well the bulb is manufactured, how you handle the bulb (always wipe your fingerprints and any other contamination off your HID bulbs), and the quality of the ballast you use to drive the bulb.
When you look closely at your HID bulbs, you see the intricate engineering and manufacturing details that make them work.
Each of these details is influenced by design and manufacturing differences that determine how well your bulbs light your marijuana plants.
These details include: the quality of quartz used to create the arc tube, the electrodes, the origins, contents, ratios, and blends of gases and metal salts in the arc tube, the glass bulb housing the arc tube, the screw-in base of the bulb, and the overall design and manufacturing standards.
Traditionally, high pressure sodium bulbs are a reddish-spectrum bulb used in flowering, and metal halide is the bluish-spectrum bulb used in veg.
These categorizations are becoming blurred as manufacturers focus on tailoring light wavelengths to better feed light to plants.
For example, Hortilux makes a 1000-watt “dual arc” bulb that features HPS and MH in one bulb.
The problem is, you can only use it with a magnetic ballast!
And no discussion of HID bulbs is complete without talking about ballasts.
You can’t just wire a bulb into an electrical outlet. You need a ballast that moderates and controls electrical current.
Ballast technology has improved a lot in the past 20 years, liberating us from heavy, noisy, hot old school magnetic ballasts so we can use modern electronic ballasts.
Problem is, the hydroponics electronic ballast industry isn’t regulated or closely held to a national standard, so a majority of ballasts marijuana growers use aren’t properly made.
Or, they’re not properly matched to the bulbs you hooked them up to.
Unless you have high-tech light meters and do side-by-side comparisons, you won’t know your electronic ballast is inferior, but most of them are.
One of the most important things you need to know about this is that dimmable ballasts can cause serious problems. This is also true for so-called dial-a-watt or select-a-watt ballasts.
The common practice is for marijuana growers to have a 1000-watt bulb fed by a dimmable or selectable-watt ballast so they can dial the bulb down to 750 or 600 watts as needed.
In some cases, “dimmable” ballasts also have an “overdrive” feature that boosts output to more than 1000 watts.
When I talked to an HID bulb engineer, he pointed out that the proper function of an HID bulb depends on it being driven by a quality ballast only at the wattage the bulb is rated for.
“When you drive a 1000-watt bulb at 1150 watts, 750 watts, anything other than 1000 watts, you’re damaging the bulb, shortening its life, not getting the light wavelengths and intensity the bulb is engineered to deliver,” the engineer explained.
If you want to use a dimmable or watt-selectable ballast, make sure to match your bulb to the selected ballast wattage, he says.
For example, if you dial your ballast to 600 watts, only use a 600-watt bulb at that setting.
Most brands of digital ballasts have poor engineering, components, and performance that waste electricity, generate the wrong light wavelengths and lower light intensity, cause bulb explosions, and make bulbs go bad faster, the engineer warned.
“The national rating service that ought to govern electronic digital ballasts, called ANSI, hasn’t created ratings or specs for electronic ballasts, so there’s no third-party monitoring of performance, specs, and components. At present, the only reliable way to power your HID bulbs for your indoor cannabis garden are to use Hortilux, Gavita, or Galaxy electronic ballasts, or use magnetic ballasts,” the engineer said.
In our next article on HID bulbs, our marijuana grow team gives you a listing of our favorite hydroponics high intensity discharge (HID) bulbs for marijuana plants, so look for that yield-increasing data soon.