Today we'll look two LED lights from Spider Farmer and the upgrades that have made them
Highly efficient white diodes like Samsung's LM301B series, offer broad spectrum white
light that doesn't mess with your eyes.
You can actually see your plants as they grow nice and full, since that light penetrates
deep into the canopy.
These cooler systems don't need noisy, energy wasting fans.
Simple designs, really are the best.
But we ARE seeing some nice features, like... dimming knobs!
The external dimming knob let's you adjust light intensity on the fly.
The SF-4000!
You get more than double the light output while costing less than two 2000s.
So this is the way to go for a compact, high output system.
The SF-1000 draws 100 watts.
It emits 250 micromoles of photons per second.
And those photons can cover 6.25 square feet in veg or 4 square feet for flowering.
That works out to 40 PPF per square foot for veg and over 62 for flowering.
How does the SF-2000 stack up?
Double the power.
Double the light and so double the coverage area.
Calculating the PPF per square foot can help to determine the proper light size for a given
coverage area.
Or select the right tent size for a given light.
Plant-usable photons drive growth.
You can spread these photons out over a large area to grow lots of plants.
But each plant will get a smaller dose of photons and growth will be less.
But reduce the coverage area and the number of plants.
Now each remaining plant gets a higher concentration of photons and the growth rate goes up.
So more photons per square foot means higher yield.
There are of course, limits to this.
And different plants have very different requirements.
Their growth phase can also be a big factor.
Not mention environmental factors like nutrients, water, humidity, temperature and CO2.
But if you're trying to match the performance from one system to another, matching the PPF
per square foot is a great starting point.
Here's a trick for your "medicinal" crops grown without extra CO2 during the flowering
phase.
When a light lists the total PPF spec you can divide by 75 to get an estimate for the
optimal square footage it can cover in a bloom cycle.
So now, how does the SF-4000 measure up?
The light output is boosted by 231%.
Logically, the coverage area should get a proportionate boost.
That works out to a veg coverage of just a over 5 by 5 feet.
And flower would be a little over 4 by 4.
Those are the tent sizes I would advise.
And when you run the numbers, the PPF per square foot checks out.
Veg would be 48.7 PPF per square foot.
Flower is 76.1 which is great for an ambient CO2 grow.
And using my tent recommendations actually gives you a boost in photon density versus
the SF-2000.
That translates into even better yield.
But Spider Farmer has a different set of coverage recommendations.
They say 6 by 6 for veg and 5 by 5 for flower.
Those tent sizes are at least 30% larger than expected when compared to the other models.
And so it seems they're pushing the light just a little bit with those coverage recommendations.
That doesn't mean this light wouldn't work well over the larger areas.
But if everything is optimized well, and you want to push your plants to the max, the smaller
tent size would achieve higher yield density.
Regardless, this is a great light and I have no complaints with product itself.
Just make sure your expectations aren't overinflated.
To help with planning your grow, Spider Farmer has supplied PPFD maps in a 5x5 tent.
These are useful.
But I wanted to take my own measurements as well.
So I opted for readings with NO side reflection showing the exact photon distribution.
I went for a 6 foot by 6 foot area on a 6 inch grid.
Using my Apogee Quantum Light Sensor I recorded the values at 12, 18, 24 AND 30 inches.
These are some impressive values.
But it's clear that 12 inches is far too close.
Super high PPFD levels won't be as useful to your crop.
It could even result in photoinhibition and even tissue damage.
The SF series LEDs really are some great lights that perform well and they'll outperform many
other LEDs.
But I want to point out a slight misconception that I observed looking at Spider Farmer's
promo materials.
In one comparison they really seemed to highlight a super high peak PPFD reading right under
the center of the light.
Other brands seem to be fixated on that same metric as well.
I have two issues with this: That peak reading is too high for even those special "crops"
that you might be growing.
It's pointless to try to go above 2000 PPFD at the canopy.
Even with CO2 you won't get the expected boost in yield.
The photosystems would be overloaded at that point.
Without CO2, there's no point in trying to exceed even 1500.
Some growers even like to peak at around 1000 PPFD.
But meanwhile, look at these corner readings.
Far too low for even, consistent growth across the entire canopy.
Hitting a super high peak in the center isn't impressive really.
In fact I can exceed 2500 PPFD with this basic 15 watt LED.
You just need to place it close enough.
Oh and here a chart for that.
But that's just one single spot.
What we need is a large amount, of total photons, evenly spread out, across a properly sized
growing area.
So this system should have at LEAST 18 inches of mounting height for even high end applications
using CO2.
As the light is raised, the coverage is more even.
Going as high as 30 inches would give you more consistent coverage from the center out
to the corners.
So depending on your plant density, layout and light cycle duration, you'll need to account
for that.
(Something to consider for auto flowers in a sea of green application.)
Now, what about that dimming feature?
The knob has markings that seem to be true.
The percentages match up to the actual wattage drawn.
I did one additional PPFD map at the 50% mark.
On my KillAWatt meter I was pulling 208 watts.
And the resulting spot readings came in right at about 50% of full power.
The dimming knob works well and Spider Farmer has some pretty good instructions in the product
To daisy chain the dimmer controls, turn off the switches for all units.
Select a primary control unit.
Plug in the RJ11 cable into the channel 2 port.
Plug the other end of the cable into channel 1 of the next light.
On each secondary unit, the back power switch needs to flipped on.
Once all units are connected, go back to your primary control unit and turn on the front
power switch.
Spider Farmer's SF series lights are an excellent value that performed well for plenty of growers.
The SF-4000 is a real powerhouse.