Best HPS Grow Lights (for Cannabis)

Growing cannabis indoors without the sun? High-pressure sodium (HPS) grow lights have long been the standard for the flowering stage.

HPS lamps produce far more usable light per watt than household incandescent bulbs, and their warm, orange-red light suits flowering plants.

They are no longer the most efficient option, though. The U.S. Department of Energy notes that LED grow lights have higher photon efficacy than HPS and cut electricity use by 24 to 30 percent compared to HPS, with less radiant heat.

HPS kits still cost less up front. Here is our roundup of five HPS grow light kits. Check each maker's current listing, since models and specs change.

PRODUCT	WATTAGE	REFLECTOR STYLE
IPower	400w	Wing Reflector
Sun System	150w	Air Cooled Reflector
Hydroplanet Horticulture	1000w	Wing Reflector
Vivosun Hydroponic	600w	Air Cooled Reflector
Hydro Crunch	1000w	Open Hood Reflector

Some Popular HPS Grow Lights

iPower 400 Watt HPS MH Digital Dimmable Grow Light

If you want a complete HPS kit, the iPower 400 Watt HPS MH system is a good place to start.

It comes with both an HPS and a metal halide (MH) bulb, a dimmable digital ballast and a wing reflector. In our experience, the timer was a little confusing.

The ballast was quiet, with no buzz. The only noise came from its quiet small fan.

You can run the HPS bulb for flowering or swap in the MH bulb for vegetative growth, using the same ballast and reflector.

Things We Like:

• Includes both HPS and MH bulbs
• Digital ballast is quiet and dimmable
• One ballast runs either bulb type

Things We Don’t Like:

• Wing reflector makes temperature control difficult
• MH bulb may fail to ignite

Sun System 150W HPS Grow Light

The Ultra Sun System 150W HPS Grow Light is a self-contained fixture sized for small spaces, such as closets and grow tents.

It gives warm, high-intensity HPS light for the flowering stage in a small package.

The vented housing helps release heat. Hang it over the center of your grow space at the height the manual recommends.

Things We Like:

• Compact fixture that's easy to set up
• Sized for closets and small tents
• Vented housing helps with heat

Things We Don’t Like:

• Low wattage limits coverage
• May receive defective HPS bulb

Hydroplanet Horticulture 1000W HPS MH Grow Light System

For a larger grow space, consider the Hydroplanet Horticulture 1000W HPS MH Grow Light system.

It is sold as a 1000-watt kit with a dimmable ballast and both HPS and MH bulbs. Check the current listing for the exact power settings and voltage it supports.

The wing reflector spreads light wide, but some light escapes from the sides.

A 1000-watt HPS runs very hot, so plan for strong ventilation.

Things We Like:

• Runs both HPS and MH bulbs
• Dimmable ballast lets you lower power for smaller plants
• Enough light for a larger space

Things We Don’t Like:

• May receive defective bulbs that may fail to ignite

Vivosun Hydroponic 600W HPS MH Grow Light

The Vivosun Hydroponic 600W HPS MH Grow Light kit is a solid middle option.

It includes both HPS and metal halide bulbs, an air-cooled reflector, an electronic ballast, hangers, a timer and cotton gloves. Check the current listing, since kit contents can change.

Peel the blue protective film off the reflector before use so it reflects properly.

Wear the gloves when installing a bulb, since oil from your skin can damage the glass. Always unplug the fixture and let the bulb cool before handling it.

Things We Like:

• Includes both bulb types
• Timer included
• Bluer MH light for vegetative growth, warmer HPS light for flowering
• Air-cooled reflector helps manage heat

Things We Don’t Like:

• MH bulb may burn out

Hydro Crunch DE01 1000-Watt High-Pressure Sodium Pro Series Grow Light System

The Hydro Crunch DE01 1000-Watt HPS Pro Series is a double-ended (DE) system for experienced growers.

It comes with an adjustable ratchet hanger, an open-hood DE reflector and an electronic ballast.

The reflector has a pre-installed double-ended socket for one DE HPS lamp. Check the current listing for whether a bulb is included and which lamp wattages the ballast supports.

Things We Like:

• Adjustable ratchet hanger allows quick installation
• Double-ended design for more light from the same wattage
• Open reflector lets heat escape

Things We Don’t Like:

• Open hood reflector may leak light
• Doesn’t come with the DE HPS bulb

How to Choose HPS grow light for growing Weed indoors

How do HPS grow lights work? The light comes from an arc inside a small ceramic arc tube (the milky white cylinder in the middle of the lamp) that contains sodium and mercury.

HPS lamps are a type of high-intensity discharge (HID) light. They need a ballast to start and run, and they get very hot.

Because HID lamps contain mercury, the EPA says not to put them in household trash. Recycle used HPS bulbs through a local collection program or retailer, and store them unbroken until then.

You have a basic understanding of these lights. Now let’s go ahead and learn the various things you have to consider before buying.

Wattage

Common HPS wattages include 150, 250, 400, 600 and 1000 watts. Match the wattage to the size of your grow space, not your number of plants.

The 1000-watt lamps run very hot. If you are new to HPS, a 400 or 600 watt lamp is easier to manage for most tents and small rooms.

A 150 or 250 watt lamp suits a closet or very small tent. Follow the maker's coverage and hanging-height guidance for your fixture.

Single versus Double Ended HPS Bulbs

The next important consideration you have to make is choosing between single and double ended high pressure sodium grow lights.

Single-ended HPS grow lights have been in the industry for decades. These lights use the normal Edison screw thread, which is easy to install.

Double-ended HPS lamps are generally more efficient than single-ended ones and tend to hold their output longer.

The drawback is cost: DE lamps and the reflectors they need are pricier, and they run hot.

For most home growers on a budget, single-ended HPS lights are cheaper and easier to maintain.

Reflectors Styles

All reflectors, whether air cooled, wing, umbrella or air cooled hood, will reflect light towards your plants. However, not all of them are capable of preventing light loss.

Also, each reflector design is suitable for a specific growing area. For example, the umbrella design is the perfect match for a large growing area.

The idea here is to find a reflector style that is best suited for your grow kit.

The first style is the air-cooled reflector. You connect ducting and a fan to its vents to pull heat out of the grow space.

The second reflector style that is very popular in the market is the wing reflector, which allows for superior ventilation. This is a very convenient choice for indoor growers.

A wing reflector gives you a pretty reliable coverage and it offers you powerful illumination as well as penetration. But this model tends to waste light from the sides.

Then we have the umbrella reflector that offers you a large coverage area and an even light distribution, making this reflector ideal for large grow spaces.

Another less common type of reflector that you can consider is the air-cooled tube design. This cool tube reflector style is good for budget indoor growers in a small grow space.

Magnetic versus Digital Ballasts

Magnetic ballasts are available in three primary types: cathode cut-out, high-efficiency core and coil, and standard core and coil.

Electronic (digital) ballasts are generally more energy efficient than magnetic ballasts. They are also lighter, quieter and run cooler, and many are dimmable.

The dimmable digital ballast may have several settings. For example, three separate settings, such as 50, 75, or 100 percent for maximum lighting control.

Final Words

HPS grow lights are simple, affordable and bright, which is why many growers still use them for flowering.

For most home growers, a 400 or 600 watt single-ended lamp with a digital ballast is a good balance. If electricity cost or heat is a concern, compare an LED fixture, which uses less power for the same light.

HID lamps get very hot. Keep them away from walls, fabric and plant tops, and keep the ballast off wet floors.

Growing cannabis is legal only for adults where state or local law allows it; it remains federally illegal in the US, and home-grow rules differ by state.

If you have been wondering, high-pressure sodium grow bulbs can be used in a greenhouse, large/small/medium grow rooms, and of course, in grow tents.

Sources

• Unlocking Plant Growth Potential with LEDs in Indoor Horticulture, U.S. Department of Energy Integrated Lighting Campaign
• Recycling and Disposal of CFLs and Other Bulbs that Contain Mercury, U.S. EPA