Get the Right MH/HPS Grow Light!

by Nebula Haze

Skip to....

• Choose the right size MH/HPS light for your space
• Where To Get Your MH/HPS Grow Light

So you’re ready to get a MH/HPS grow light? Perhaps you want to add an MH/HPS light to your existing setup, or perhaps this is your very first grow light for growing cannabis.

MH/HPS is a great choice for growing cannabis! These have been considered the “golden standard” for indoor cannabis growing for years, and there’s an abundance of information, guidance and help for MH/HPS growers.

MH stands for "Metal Halide" and HPS stands for "High Pressure Sodium." These are two specialized types of bulbs that are great for growing plants, from a class of lights known as HID (High Intensity Distcharge).

MH lights are often used in the cannabis plant's vegetative stage (first stage of life) and HPS is often used for the flowering stage (second stage of life). Either type of bulb can be used for the entire cannabis plant's life span, though HPS is much more common is growers choose just one. Many grow light ballasts now allow you to use both MH and HPS in the same hood/reflector - just take one bulb out and plug in the other bulb - you're good to go!

Before I got any further, it's important that you...

 

Choose the right size MH/HPS light for your space

 

150W MH/HPS

• Coverage Area: 2' x 2' (0.6m x 0.6m)

• How Far From Plants? Keep 7 inches (17cm) away from tops of plants

• Average Yields: 75 - 150 g (2.5 - 5 ounces) - less for beginners, more for the pros - get the biggest yields by filling the entire grow area with a wide even canopy and remember that the strain (genetics) you grow with also makes a huge difference in your final yields

• 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.

 

Get a 150W HPS Grow Light

 

---

 

250W MH/HPS

• Coverage Area: 2' x 2' (0.6m x 0.6m) up to 2.5' x 2.5' (0.8m x 0.8m)

• How Far From Plants? Keep 9 inches (23cm) away from tops of plants

• Average Yields: 125 - 250 g (4 - 8 ounces) - less for beginners, more for the pros - get the biggest yields by filling the entire grow area with a wide even canopy and remember that the strain (genetics) you grow with also makes a huge difference in your final yields

• Notes: Some (but not all) 250W MH/HPS have a “Built-In Ballast,” which means everything is actually attached together and you just plug the light directly into the wall. Some 250W HPS lights have a traditional ballast, which means that the ballast is a separate piece from the hood. In general, it's better to get a light with a separate ballast if you can - they are more efficient, cooler, and spread their light over a bigger area. 

 

Get a 250W Grow Light (with both MH & HPS bulbs)

 

---

 

400W MH/HPS

• Coverage Area: 3' x 3' (0.9m x 0.9m) up to 3.5' x 3.5' (1m x 1m)

• How Far From Plants? Keep 12 inches (30cm) away from tops of plants

• Average Yields: 200 - 400 g (7 - 14 ounces) - less for beginners, more for the pros - get the biggest yields by filling the entire grow area with a wide even canopy and remember that the strain (genetics) you grow with also makes a huge difference in your final yields

• Notes: 400W is one of the two most popular sizes for small-scale growers (along with 600W). A 400W grow light runs relatively cool compared to most other HID lights, but packs quite a punch when it comes to yields. Generally it’s a good idea to set up an exhaust for a 400W grow light to manage temperatures.

 

Get a 400W Grow Light (with both MH & HPS bulbs)

 

---

 

600W MH/HPS

• Coverage Area: 3.5' x 3.5' (1m x 1m) up to 4' x 4' (1.2m x 1.2m)

• How Far From Plants? Keep 16 inches (40cm) away from tops of plants

• Average Yields: 300 - 600 g (10 - 21 ounces) - less for beginners, more for the pros - get the biggest yields by filling the entire grow area with a wide even canopy and remember that the strain (genetics) you grow with also makes a huge difference in your final yields

• Notes: 600W is one of the most popular sizes for small-scale growers (along with 400W). A 600W grow light is the most efficient of all HID lights, which means it produces the most amount of light per watt of electricity. To prevent heat problems, I would not recommend getting a 600W light for a regular grow room without installing an exhaust setup or some other way to control temperature.

 

Get a 600W Grow Light (with both MH & HPS bulbs)

 

---

1000W MH/HPS

• Coverage Area: 4' x 4' (1.2m x 1.2m) up to 5' x 5' (1.5m x 1.5m).

• How Far From Plants? Keep 21 inches (53cm) away from tops of plants

• Average Yields: 500 - 1000 g (17 - 35 ounces) - less for beginners, more for the pros - get the biggest yields by filling the entire grow area with a wide even canopy and remember that the strain (genetics) you grow with also makes a huge difference in your final yields

• Note: 1000W is the biggest standard HID grow light size. A 1000W grow light is extremely powerful but can also get very hot. To prevent heat problems (which can adversely affect your plants), it is important to set up an exhaust setup or some other way to control temperature.

 

Get a 1000W Grow Light (with both MH & HPS bulbs)

 

---

 

Where To Get Your MH/HPS Grow Light

Skip right to...

All-In-One Grow Light Kits

• ​iPower
• Apollo
• Horizon (250W only)

Piece It Together Yourself

1. Pick Ballast
2. Pick Bulb
3. Pick Hood/Reflector

Specialty grow lights like MH/HPS grow lights can be found online as well as in person at hydroponic shops and some gardening stores. Below I will share some of the trusted brands that work great for growing cannabis, so you can use the information you learned above to get a grow light that suits your needs and budget.

When getting an MH/HPS grow light, you need to choose whether you want to get an “All-In-One” kit which has all the individual parts packaged together, or whether you’d like to get the 3 pieces separately.

Building it yourself is actually surprisingly easy, too - you just get 3 parts that match each other and plug them together. There’s no special tools or assembly acquired - everything connects easily together as long as you get matching pieces. It’s as simple as plugging in your ballast and screwing your bulb into your hood/reflector.

Some growers like to mix and match to better suit their needs, while others prefer to get it all at once so no thought or research is required. And all the information you need is below...

All-In-One Kits - iPower & Apollo

iPower & Apollo Brand All-In-One MH/HPS Kits are remarkably inexpensive, “okay” quality grow lights with 2 year warranty.

The all-in-one kits have all the parts you need so you can just plug in your grow light and go. All-In-One kits are generally not as long-lasting or sturdy as getting parts from trusted brands and putting the pieces together yourself.

Unfortunately some growers who purchase iPower or Apollo grow lights get duds or run into problems, yet with quick returns from Amazon.com and a 2-year warranty, iPower & Apollo offer some of the least expensive MH/HPS grow light options, and are great for a beginner’s first grow since they won’t break the bank.

With any grow light, including Apollo or iPower grow lights, make sure that you immediately test your light on arrival to make sure everything works well before starting your grow. 

Please note! Some of the higher powered kits (like the 1000W grow lights) can cause radio interference.

 

---

 

Popular iPower Kits

Some growers feel that these iPower kits aren't as good as the Apollo ones (listed below), but so far we haven't seen any convincing evidence either way. In either case, all grow lights purchased from Amazon are protected by the iron-clad Amazon.com guarantee. We recommend that you test any new grow light that you purchase online immediately - Amazon will replace any faulty parts or bulbs, but you need to contact them within the first 30 days!

 

---

 

 

---

 

Horizon - 250W 

The only recommended model from this company is their all-in-one 250W MH/HPS grow light. It can be difficult to get a digital all-in-one model of 250W that does both MH & HPS grow lights.

The 250W light from this company seem to do the trick. It's a great value for the low price!

250W All-In-One MH/HPS

 

---

 

While these all-in-one kits are cheap and convenient, most growers will get a superior grow light by piecing the 3 parts together, as follows...

 

Build It Yourself: Here’s What You Need

1. Ballast

2. Bulb

3. Hood/Reflector

Most important point to remember: Make sure that all three pieces match each other. So for example if you get a 400W ballast, it MUST be matched with a 400W bulb and 400W-compatible hood/reflector. Do NOT mix and match unless you want a fire. Some special or unusual ballasts require special bulbs - always read the manufacturer’s instructions when in doubt! I’ll include more information about different bulbs below.

Need more details than this quick walkthrough?
Read the ultra-detailed guide on picking out a MH/HPS Grow Light

Here’s a summary of what I recommend for new growers to make your life easier...

1.) Pick Your Ballast

Make life easy on yourself by getting a great ballast...

• Digital

• Dimmable

• Supports MH and HPS bulbs

This gives you the most flexibility as you can use either type of bulb, and digitally control how intense you want the light to be at any moment.

I highly recommend getting the best ballast you can afford, as better ballasts last longer, are easier to use, and offer the "bells and whistles" you'll wish for after you start growing. Even the most expensive ballast will pay for itself after a single successful harvest.

Trusted Brands For Ballasts (best of the best)

• Lumatek - some ballast have trouble with radio interference (AM radio, etc)

• GGL

What is the difference between a “digital” and “magnetic” ballast?

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. Digital ballasts are also more likely to be compatible with more types of bulbs, where a magnetic ballast needs special magnetic ballast compatible bulbs and will burn out the wrong type of bulb.

What is a “dimmable” ballast?

A dimmable ballast allows the grower to adjust the ballast to put out less light (and use less electricity) when plants are small and don't need full-strength light yet. This can shave quite a bit off your electricity bill and make it easier to nurture young plants. If you get a dimmable ballast, make sure your bulb can also be dimmable.

Can a ballast support both MH and HPS bulbs?

Some ballasts only support one type of bulb, while others are compatible with both types of bulbs. For most new growers, I recommend getting a ballast that supports both MH and HPS bulbs so you can interchange them easily between the vegetative and flowering stage. It is possible to grow a cannabis plant from seed to harvest on either just MH or just HPS. If you’re going to choose just one, I recommend getting HPS since it’s more efficient (puts out more light for the amount of electricity used) and will get bigger harvests in the flowering/budding phase. But it is also possible to grow from seed to harvest with just an MH bulb. Every ballast will clearly state what types of bulbs it supports, so no guesswork needed.

2.) Pick Your Bulb

Trusted Brands For Bulbs:

• SunMaster

• Digimax

• Lumatek

Never buy used bulbs! MH and HPS bulbs lose efficiency the longer they’re used. Turning bulbs on and off frequently will also wear them out. A bulb that has been used for a few grows will put out significantly less light than a new bulb. Because of this, it’s recommended that growers replace their bulbs with a new one every 3-4 grows and avoid ever buying a used bulb. Some sellers will actually replace burnt out bulbs within a certain time period, so definitely take advantage of new bulbs with guarantees if you can!

What does “digital” or “magnetic” mean when it comes to HID bulbs?

Make sure that if you have a “magnetic” ballast that you match with a bulb that is compatible with magnetic ballasts. A digital ballast can support both types of bulbs.

What does “deluxe” mean?

Some companies use the term “Deluxe” to describe some of their higher end bulbs. Deluxe bulbs are generally considered to be “spectrally enhanced” which means they provide a little bit more usable light to your plants for the same amount of electricity. They are meant to enhance growth without using more energy, and they tend to cost quite a bit more. Some manufacturers claim their Deluxe bulbs are 10% brighter than their non-Deluxe counterparts.

3.) Pick Your Hood/Reflector

Trusted Brands For Hoods:

• Sun Systems

• Horizon

What is the difference between wing, cooltube and air-cooled hoods?

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.

Cool tubes are built so that the bulb is contained in a tube. They are meant to be hooked up to an exhaust (via ducting) to pull all the heat away. Cool tubes are less likely to cause hot spots on the plants than wings, and can fit in smaller spaces than any other type of hood, but they tend to be limited at reflecting the light. Notice how there is usually only a small reflector built into the top of the tube. While this does a pretty good job at reflecting light, other types of hoods will tend to reflect more light down to the plants.

Air-cooled hoods are great for capturing hot air and keeping them away from the plants. They are also able to be hooked up to an exhaust system. One of the advantages of air-cooled hoods when growing cannabis is they have a big, smooth reflecting surface to reflect a great deal of light down at the plants (without also sending heat down at the plants). This allows the plants to get more light from the same bulb.

What are “XXL” hoods?

XXL hoods are designed to be wider so that they reflect light over a bigger area with the same grow light bulb.

 

---

 

Jump to...

Complete MH/HPS Grow Light Tutorial

7 Tips to Growing Top-Shelf Buds

Which Grow Light? | Cannabis Grow Light Guide

How to Fix 99% of Cannabis Growing Problems

 

 

---