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Can't share a shot because I have a plant limit, but I 'believe' it will cover 16 plants with no problem.
Back in the game.....need 2x4 lighting advice!
- Thread starter HotBunz1
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Just share half the picture at a time.
"kind of crapping on his purchase here lol."
Respectfully disagree. I am not crapping on his behavior or his decision. I'm giving an opinion about a product that will most likely not serve his purposes.
My words were strong because I wanted to get his attention. Some posters start a thread and don't return so I used direct, forceful language. That approach appears to have been successful.
I'm glad you responded to my posting. I didn't go into detail because many times a thread gets abandoned and I didn't want to spend the time writing a lengthy comment in a "dead thread".
Per my previous posting, the 2020 Mars SP3000 is a really nice light. I bought one when I started growing again in 2021 and it served me well. The 2024 Mars SP3000 is a different light than the 2020 Mars SP3000.
In 2017, I bought a tent kit, did one grow, and archived the tent until 2021. The cannabis world was very different in 2021 than it was in 2017 and one of the biggest changes was that blurple was on the wane and "white" LED had taken over. I had a Kind XL600 blurple and got the PPFD map from Kind. "All it took was just one look" and I knew I wanted a new light. After checking out the market, I bought the Mars SP3000.
Part of my learning process was to read and watch everything I could find on grow lighting and, over the next few months, I switched to Growcraft X3 lights, one for veg and one for bloom. I also use a Vipar XS 1500, a Rapid LED Royal Blue puck, and a pair of Vipar Glow R80's during the course of a grow. Last summer, when I was looking for a replacement for my X3 flower light, I spent a few days looking into the market. All in all, I've spent quite a bit of my life learning about grow lights over the past four years.
When I did my "market search" last summer, I was looking for a very high output light for a 2' x 4' that had a high percentage of red in the spectrum. My 2020 Growcraft lights are nice lights but I wanted a light that could get 1kµmol on my canopy from a hang height of 18". During my search, I check Mars and saw that they had the SP3000R and it looked like it was exactly what I wanted - a dedicated flower light (huge amount of red and, so it would appear, a smattering of blue) that was only $200 and that would fit in my tent. Great.
One small issue–the PPFD map is awful for a tent grow. The PPFD map for the light is shown below and, as you can see, there's a 1' strip in the center that gets gobs of light but then PPFD values collapse along the edges. That design is acceptable in a greenhouse where lights are suspended from a ceiling but that's not a PPFD map I want to tangle with in my tent. I( use a variety of lights over the course of a grow and I measure light values (pretty much) daily.)
Per the graphic below, in many locations, the amount of light hitting the canopy may be 3 times higher than the amount of light hitting the canopy just a few inches away. No thanks.
How does that work out in real life? It works out just fine because the grow using these lights will hang them side by side, across the ceiling, and, with all of these lights, the PPFD map evens out. If that same light is put in a grow tent, you will have just the one light and its very uneven map.
I bought the light and tried to run it by itself as well as with my 2020 SP 3000 (full spectrum) but I could not get the PPFD map I wanted and the heat output was very high so I shipped it back.
The PPFD map for the 2024 Mars SP3000 is show below. The PPFD map for this light is very uneven.
Looking at the graphic above. In many locations, the amount of light hitting the canopy is at least twice as high as the amount of light hitting the canopy just a few inches away. That's brutal.
How does that work out in real life?
Just fine because the grow has these lights hanging side by side, across the ceiling, and, with all of these lights, the PPFD map evens out. If that same light is put in a grow tent, you will have just the one light and a very uneven map.
Below is the PPFD map from the Mars FC4000EVO (picked at random). At 12", PPFD is about 1000 and about 800 along the edges. The 1k value is obviously lower and the 800 value higher than the 3000R and that's good because that means that the light cast is pretty even.
[edit]
Heavy edit because I saw your posting that the 4500 is too long for your tent. Sorry to hear that. :-(
While writing this, I wrote about the SP3000 form factor, saying that the "single bar" design is a joy to work with because it never gets in the way. In your case, you need its smaller size to fit in the tent.
Have you considered the Vipar XS3000? It's only 38" long and consists of two XS 1500's held together with a bracket? The price is similar to the SP but the PPFD map, while having lower peak values, has a more even light cast.
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My last grow was in 2017. Back then COB LED's were all the rage. Fast forward to today and I agree the lighting has radically changed with the majority to diode LED's. I would have gladly built another custom COB fixture for the enclosure but cost wise it didn't make sense as an off the shelf unit more budget friendly. During the course of my research I compared the PPFD maps to both the Mars SP3000 and Spider's 4500 and while I am a little concerned with the radicle difference in intensity away from the center of the SP3000 keeping my footprint in mind it was the best choice out of my options. I believe it will work great as I get my first grow in 8 yrs underway. Heck I'm going to go out on a limb and say I'll get 12oz dry off 1 plant from under the Mars SP3000. I appreciate you taking the time and offering your advice.
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"kind of crapping on his purchase here lol."
Respectfully disagree. I am not crapping on his behavior or his decision. I'm giving an opinion about a product that will most likely not serve his purposes.
My words were strong because I wanted to get his attention. Some posters start a thread and don't return so I used direct, forceful language. That approach appears to have been successful.
This light is more than adequate for a 2 x 4 space.
At 24 inches that's providing more than enough light intensity, even to the edges. To even utilize that high PPFD he'd have to supplement with CO2, otherwise it'd be a waste of photons.
Canopy management is going to play into maximizing the light, but that's argument to be made for any grow light.
"12oz dry off 1 plant from under the Mars SP3000" - I would be very surprised if you could attain that. It's not a question of your skill—it's a question of physics.
Plants make food via photosynthesis. Light and CO2 are inputs to photosynthesis and, per the table below, the more light, the greater the yield (assuming that light is the constraining factor). Conversely, when light levels drop, photosynthesis drops, glucose production drops, and plant growth slows.
With the 2024 SP3000, you have a strip of usable light that is roughly 1' wide and 3' long. That's 3 square feet out of an 8 sq foot tent or 40%±. The other 60% of your tent will have light levels that are inadequate for flowering cannabis.
In essence, by using this light, you will have less usable grow space than a 2' tent.
And that's at 24" hang height. The nature of LED grow lights is that the PPFD map smooths out as hang height increases. If that light is lowered, it will get even more uneven.
Here's how I see the PPFD numbers at 24":
The PPFD reading in the center of that area is 1373µmol. With the exception of the spurious 1400± values, the other 5 sq feet of grow space have PPFD's < 600, with some in the 400 range. The impact of this is that when you reduce the wattage so that the light level in the center strip is low enough to not cause damage to your plants (1000µmol for sake of argument), that 25% reduction (1373 to 1000) means that the other 60%± of your grow will have PPFD levels in the low-400's (550-25%=410)
I'll label the above as "the best case scenario" because very, very few grower actually get 1kµmol across their canopy. More likely 900, 800, 700, etc. If you light your grow to even 900µmol, that means that the other 60% of your grow is about 40% below 600, or 360µmol. That's DAWA - dark as a whale's ass. My plants are at 400 by day 15.
Doing some rough math, in the best case scenario, you have 3 ft at 1000µmol and 5 feet at 400 which is an average of 625µmol. Drop your max PPFD to 900 and you're looking at an average of 560µmol in the 8 sq foot area.
From one of the papers uploaded:
I created the table based on the yield curve in the Frontiers paper and I started at 600µmol because that's the conventional wisdom for the lowest PPFD a cannabis plant should receive in flower. Per the table, at 600µmol the crop is 35%± smaller.
If you check out the PPFD map for the Vipar XS3000, you'll see that the PPFD map is very different. The reason for this is that the light is designed to be used in a tent and because Vipar did a superb job designing the XS 1500 Pro.
The SP3000 has a huge drop off as soon as you move off center. In the 900µmol use case I outlined above, the PPFD map for the 2024 Mars SP3000 will be insufficient to adequately light a cannabis grow in flower.
In contrast, the PPFD map of the Vipar shows a very different story. At 12" hang height, the average PPFD is 50% higher than the average PPFD from the Mars.
If the 2024 Mars SP3000 is used, if the center of the grow is receives 1000µmol then the average PPFD in a 2' x 4' tent will be about 625µmol which is slightly above the minimum level recommended for flowering cannabis. In the most likely scenario, PPFD levels will be inadequate for flowering cannabis. A grower using this light in a tent should expect modest yields.
In contrast, the Vipar XS 3000 is similarly priced, has a similar spectrum, and, since it was designed for use in a tent, the PPFD map is extremely even. At typical hang heights, the Vipar generates about 50% more usable light than the 2024 Mars SP3000.
In the past I had bigger yields(+12) with less light.
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625 µmol at 18 hours (assuming flowering autoflowers) is still 40 DLI, which is PLENTY of light for flowering.
It's also on the cusp of needing supplemental CO2 to provide much actual use to the plants above that
Look at the old Mars II 1600 for example. At 18 inches it was barely hitting 1000 PPFD, then quickly drops off as you near the edges. And if you ever ran one of these, you know nobody was running these 18 inches above their canopy, you set this beast at the top of the tent and hoped your tent supports were strong enough to support it (it was a really heavy light lol.) And yet lights like this grew some great weed in 4 x 4 and 5 x 5 tents.
A lot of it too depends on how many plants are in the tent, how they are staggered, how they are trained, etc.
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I run this light at full.
I had to raise it to 36" to get 45 DLI at 18 hours.
The center hot spot is quite a bit wider at that height. The rest of the light bounces off the walls, and there is some loss in each reflection (about a stop and a half) but it eventually bounces back to the plant or dissipates as heat.
I had to raise it to 36" to get 45 DLI at 18 hours.
The center hot spot is quite a bit wider at that height. The rest of the light bounces off the walls, and there is some loss in each reflection (about a stop and a half) but it eventually bounces back to the plant or dissipates as heat.
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