Spider Farmer G8600 Review

The Spider Farmer G8600 is a large LED bar grow light with up to 860 watts of power. In my tests, it had excellent efficiency, and it has a record setting price! However, there is a lot of light in the center, so the minimum height above the canopy may be an issue for some growers in tents. I ran several PAR and ePAR tests to simulate different ways that I could imagine using the Spider Farmer G8600 with and without supplemental carbon dioxide in a 5’ x 5’ grow space.
Spider Farmer has two lines of LED bar fixtures: The SE series and the G series. The SE series use name brand components with Samsung LM301b and Osram diodes. The G series uses lesser known Bridgelux diodes. They are the same diodes that Mars Hydro uses on their FC-E series fixtures. Although Bridgelux diodes are lesser known, they perform very well.
Each LED bar has 336 diodes. That gives the G8600 a total diode count of 2688. With a published 860 watts, that equals 3.13 diodes per watt or about 0.32 watts per diode. Like many fixtures, the G8600 features full spectrum diodes at 3000K and 5000K along with 660nm deep red diodes.
The Spider Farmer G8600 is shipped disassembled with 8 LED bars and two frame pieces. It assembles by clicking the LED bars into plastic brackets on the frame pieces. It only takes a couple minutes, and the design allows them to save considerable costs on shipping.
The cost for the G8600 is truly remarkable. The current list price is only $626.99. We have an 8% discount code on Spider-farmer.com, CCFC. With our code, the cost you’ll pay is only $576.83. In my official ePAR test, the G8600 delivered 1964.2 µmol of usable light. The cost efficiency sets a new all-time record for any LED light I have tested! The G8600 has a cost efficiency of only $0.29/µmol!
With over 800 watts of power, the G8600 is designed to cover a 5’ x 5’ area. However, even in that space, it had to be hung very high above the sensor in my official test. I set up my official PAR and ePAR tests at the hanging height that delivers a maximum PPFD of 1000 µmol/m2. This is the level that is safe for growers without supplemental carbon dioxide. For the G8600, the maximum PPFD was 1000 µmol/m2 at 68cm or about 27in above the sensor, which is near the limit of my testing set-up.

The official PAR and ePAR maps are exceptional. The average density is really high, and there is a good distribution of light. However, that is largely a result of the very high hanging height. Growers in tents will have a difficult time maintaining the minimum hanging height revealed by my tests, which is 68cm or about 27in. At a lower height, you risk light burn in the center, or you could opt to run the G8600 somewhat dim.

I lowered the height to 41cm, about 16in. This is a distance that growers in tents will have an easier time maintaining. I also lowered the dimmer to about 70% to get the maximum PPFD back down to the 1000 µmol/m² limit. Measuring the power draw is a more accurate way to set the dimmer. The power draw was 645 watts.

The PAR and ePAR maps in these tests are good, but the corners fall below the 500 µmol/m² threshold for the most efficient photosynthesis. However, it is not surprising for a fixture that is only pulling 645 watts in a 5’ x 5’ area. In fact, the G8600 had phenomenal photon efficacy in this test, 2.50 µmol/w. Few lights on the market could produce as much light with only 645 watts. The issue is that the distribution is not the best. There is too much light in the middle, which limits how much power I can send through the dimmer and still stay within the 1000 µmol/m² limit. At 16” above the canopy, I would like an LED bar fixture to be able to distribute more light to the corners.

I decided to run a final ePAR test at the same 41cm (16in) hanging height with the dimmer cranked back up to 100%. This will deliver more light to the corners, and everywhere else. It pushed the maximum ePPFD up to 1308 µmol/m², which is safe only for grows with elevated levels of carbon dioxide.

The performance of the Spider Farmer G8600 is impressive in several ways. The number that pops from this test is the Photon Efficacy of 2.55 µmol/m². The average ePPFD of 948.2 µmol/m² is also notable, however, with a maximum PPFD of 1308 µmol/m², growers with supplemental carbon dioxide may want an even higher average. Again, the main drawback is that the light is concentrated in the center and drops off significantly toward the edges and corners. The minimum ePPFD is less than 43% of the maximum ePPFD in this test.

The PAR and ePAR tests show both the strengths and relative weaknesses of the Spider Farmer G8600. Although it has a record setting price point, the G8600 is a powerful light that is incredibly efficient. It can generate plenty of light to fill a 5’ x 5’ grow space. However, the distribution of light is not its strength. If you have the vertical space to allow the light to spread out, then it may be the best option for you. However, if you are in a grow tent and hope to run the G8600 at full power, you’ll have to keep your plants short or seal the tent and add carbon dioxide.

After the PAR and ePAR tests, I measured the surface temperatures. The tops of the LED bars hit 46.8C (116.2F). The Spider Farmer driver hit a high temperature of 58.2C (136.8F). Like all grow lights, the amount of heat that the G8600 will add to your space is a function of the power draw. If you run it at full power, about 835w in my tests, it will generate about 2,850 BTU/h (watts*3.41=BTU/h).

I also tested the dimmer. There is a continuously variable dimmer knob mounted with the driver. However, on the model that I tested, the fixture reached full power when the knob appeared to be set at about 80%. Power and PPFD did not change between an apparent 80% and 100%. Possibly as a result of this, throughout the dimming range, the power and the PPFD were higher than the apparent dimmer position. However, there is a consistent relationship between power draw and PPFD output. If you want to accurately measure the dimming on any fixture, it is better to use a power meter rather than rely on the apparent dimmer setting.

The Spider Farmer G8600 is an incredible deal. It shatters the 30 cents per micromole barrier. Micromole per micromole, you will not find a better deal. However, be aware that you will need a lot of vertical space or supplemental carbon dioxide to be able to take advantage of all of those micromoles.