Metal Halide vs HPS For Flowering: Comparison

Disclosure: As an Amazon Associate I earn from qualifying purchases. more info

One of the most commonly asked questions which new weed growers have is whether metal halide or HPS grow lights are best, especially when it comes to flowering.

Now, both metal halide and HPS grow lights are types of HID or high intensity discharge lights, which means that they do have a whole lot of power. However, when it comes to metal halide vs HPS for flowering, which is best?

Generally speaking, both of these types of light, MH and HPS, are good options to go with, but for the most part, due to a couple of different reasons, HPS are the better option for flowering.

Simply put, HPS grow lights tend to produce larger plant yields and higher quality results as well. Let’s take a closer look both types of grow lights and what they bring to the equation.


Metal Halide Grow Lights

Metal halide grow lights are some of the more popular ones out there, and for good reason. One defining characteristic of metal halide grow lights is that they give off more white and blue light when compared to HPS lights.

Metal halide lights tend to be considered great full spectrum grow lights, and thy are great for the vegetative state, as they usually produce really lush and thick vegetation which is great for getting weed plants ready for the flowering stage.

Something that is cool about metal halide bulbs is that they can often be customized and changed. They usually come with large ballasts, often complete with cooling systems in order to ensure that they do not overheat.

Moreover, there are certain metal halide bulbs which give off more blue and white light, best for vegetation, and then there are others which give off more red light, best for flowering and producing high yields.

In terms of lumens, which is very important for weed plants, a normal 1,000 watt metal halide bulb will usually produce between 80,000 to 110,000 lumens, which is a lot, but then again, there are more powerful and efficient options out there.

HPS Grow Lights

HPS stands for high pressure sodium, and this is another specific type of HID or high intensity discharge light.

The HPS grow lights are usually associated with having a lower outpout of white and blue light, but a higher output of red light, at least comparatively speaking, although the newest ones put out a heck of a lot of light across the full spectrum.

High quality HPS grow lights are specially engineered to produce a heck of a lot of lumens and a lot of red light, both of which are beneficial for marijuana flowering.

On average, a 1,000 watt HPS grow light will put out between 130,000 and 155,000 lumens, which as you can tell, is a lot more than the metal halide counterpart.

The fact that HPS grow lights come on average with between 25% and 40% more lumens per the same watts, it tends to make for a better flowering grow light.

Simply put, the higher the lumen output, the more light intensity the pot plants are getting, and this then usually leads to higher yields, denser buds, and a higher THC content too.

HPS lights tend to have a much longer lifespan overall, and stay much brighter for longer, when compared to MH lights.

Metal Halide vs HPS – A Quick Lowdown

Alright, so when it comes down to it, as you might have gathered by now, high pressure sodium lights are generally considered much better for flowering that metal halide grow lights, and here is why;

  • High pressure sodium lights produce a higher amount of photosynthetically active radiation (PAR) than MH lights, which all plants need to perform photosynthesis, which in turn leads to faster, better, and more efficient growth in all regards.
  • HPS lights are about twice as efficient in terms of power use as metal halide lights, so in other words, they run cooler and they cost you much less money to run as well.
  • High pressure sodium grow lights produce up to 40% more lumens per watt than metal halide lights, and this then leads to much higher yields when marijuana is flowering.
  • What is also interesting is that although metal halide lights are known for having high outputs of blue light, comparatively speaking, they actually do not create a discernible increase in vegetative growth.
  • At the end of the day, due to various reasons, HPS grow lights produce much better yields when flowering marijuana plants.

Note: We have covered our favorite 1000 Watt bulbs for flowering over on a separate article here.


Yes, you can use metal halide lights if you want, but generally speaking, high pressure sodium grow lights are way better for the flowering stage and produce much bigger yields.

Moreover, they are also much cheaper to run, and more versatile too. Most would agree that HPS grow lights are better than MH lights in more or less every way imaginable.


My passion for the sticky icky started nearly a decade ago, and it all began when I first laid my eyes on the beauty that is the marijuana plant.

I cover all aspects of growing from equipment recommendations to plant health/care tips to help both new and experienced growers.