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MarsHydro Mars II Series 400W LED Grow Light

By |2018-10-08T22:52:58+00:00September 12th, 2018|LED Grow Lights|0 Comments

In our previous MarsHydro post, we covered the Pro II Series LED grow lights. Now it’s time for a look at the little brother of the Pro II, MarsHydro’s Mars II Series.

The Mars II series comes in various sizes from 400W to 1600W. And like all Mars lights, it’s very competitively priced.

In this review, we’ll concentrate on the full spectrum MarsHydro Mars II 400W LED grow light.

A 250W HPS replacement which covers 2.5’ x 2.5’ for flowering, or up to 4.5’ x 4.5’ for veg stage.

Read on to see how the Mars II lights differ from MarsHydro’s other offerings, what the Mars II 400W can do and who this range is aimed at.


Full disclosure: This is a sponsored post. MarsHydro asked us to help promote its eBay factory store. Since we know Mars lights are already popular with our readers and we’ve always written positively about them in the past, we were happy to agree to write a series of posts. Moreover, while we have been paid to write these posts, the content has been left up to us.

If you missed it, the first post in this series explained why you should be heading to the eBay store instead of Amazon (main reasons: it’s cheaper; some models aren’t available on Amazon). In this post, in our previous posts, and in future posts, we’re introducing you to some of MarsHydro’s best and most popular lights.


MarsHydro Mars II 400W: What do you get for your money?

marshydro mars II 400W - review - smaller image

Buy on MarsHydro eBay Store

As usual with MarsHydro, if you buy the Mars II 400W, you’re getting a quality light at an attractive price.

For a draw at the wall of just ~162W it can replace a 250W HID light and covers a flowering area of 2.5’ x 2.5’. We’re talking bright,12-channel full spectrum light, including IR (infrared).

It also has separate Bloom & Grow switches, to help you save a little money on running costs if you choose to boost the red end of the spectrum only during the flowering stage.

Where the Mars II Series differs from the Pro II Series is partly in price — a little lower — but mainly in the lack of reflector cups.

The Pro II lights use name brand chips from Epistar (and even CREE, for a few models) combined with reflector cups. While the Mars II lights also boast 80 very bright 5W SMD Epistar LED chips, there are no Mars II models available with CREE diodes and the secondary optics have been dispensed with.

However, coverage and brightness are still excellent — and Epistar SMD LED chips are not to be sniffed at.


What are SMD LED chips?

Surface Mounted Device LEDs are LED chips fused to a printed circuit board. With up to three diodes per chip (usually red, green, blue), SMD LEDs are very versatile and allow for close control of the color output.

They’re also brighter, more efficient and longer lasting than the traditional DIP LEDs that many of the original LED grow lights used. (The shortcomings of the early DIP LEDs are what led to a lot of the myths that are still being repeated today about LED grow lights being poor for growing cannabis).

And they emit light at a better angle, usually either 90 or 180 degrees. (For the Mars II Series lights the view angle is an even more optimal 90 – 120 degrees.)

Which is all why they’re the popular choice in today’s grow lights.

COB (Chip on Board) lights are similar. Having generally up to 9 diodes per chip, they are even brighter and even more efficient, but less versatile — each COB chip is a single light source that outputs a fixed (though full) spectrum.

The other advantage SMD LEDs have is that they can be packed closer together than COBs, giving fewer hotspots and more even coverage than some COB grow lights.


While the Mars II Series doesn’t have reflector cups or CREE chips, this series isn’t necessarily a drop in quality. More like an alternative choice.

Sure, the reflector cups mix the colors and even out the footprint better than SMD LEDs alone — reflectors mean the angle of light from the Pro II Series LEDs is 100 degrees, so that less of it is lost.

However, with the Mars II you’re still getting some high PAR values for your money (see below) — higher, in fact, than the Pro II. Even if, as stated above, the light isn’t as well directed and more of it is lost.

However, if you have light movers too, you could still opt for the cheaper Mars II and even out the coverage nicely.

Brightness and intensity

So what exactly are the Mars II 400W’s PAR values?

Here are the figures:

  • 820 umols when hung at 12” (flowering stage)
  • 752 umols at 18” (vegetative stage)
  • 350 umols at 24” (seedling/veg stage)

Of course, those are the figures for the center of the footprint. For a better idea of values across the whole footprint, check the diagram below:

marshydro mars II 400W footprint diagram

MarsHydro Mars II 400W footprint diagram

What else do we like?

Like the Pro II Series, the Mars II lights also come with a 3-year warranty. And servicing is handled by local repair centers (for most of our readers). A slightly longer warranty than for some of the other MarsHydro lights.

Other features worth noting:

  • 50,000 – 100,000 hour lifespan, thanks to SMD technology
  • Spectrum includes IR to help achieve higher yields
  • ETL/CE/RoHS certified for safety—parts inside are fireproof
  • Zener protected chips, so that even if one fails the light still works
  • Comes with hanging kit, instructions and region-specific power cord

Any downsides?

Not as quiet as the Pro II Series, with its 58dB noise level. But still pretty quiet.

The Pro II Series promises yields of up to 2.0g per Watt; whereas the Mars II only quotes yields of up to 1.8g per watt.

And, as with the Pro II Series, there’s no UV in the spectrum. However, it’s not so difficult to add a bit of UV light yourself, if you’re convinced of the benefits — there are plenty of cheap UV lights on the market that can be easily added to your setup (even aquarium lights will suffice).

Also worth noting is that the Mars II 400W runs slightly cooler than the Pro II Series equivalent — which could be either an advantage or a disadvantage depending on the climate where you’re growing.

Our overall verdict

MarsHydro markets the Pro II Series as the best choice for commercial growers, with its highest PPFD figures. And the difference between the two ranges is more pronounced in the more powerful models.

However, when comparing the Mars II 400W and the Pro II 400W, we think it’s more a matter of personal preference as to which one you should choose.

The MarsHydro Mars II 400W is another excellent accessibly priced full spectrum grow light for the indoor home grower. If you have a flowering canopy of 2.5’ x 2.5’ to cover, this will do the job without emptying your wallet. PAR values are plenty high enough to give your cannabis crop its Daily Light Integral.

However, if you want a quieter light with slightly higher yields, go for the Pro II Series 400W model. PAR values aren’t as high and footprint isn’t quite as large. But the light emitted is better directed and the Pro II offers slightly different Bloom/Grow spectra to the Mars II.

In either case, make sure you check out the prices on MarsHydro’s eBay factory shop for cheaper prices than Amazon and the occasional sale or combo deal.

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