Greetings again folks and sponsor
@Medic Grow LED,
This post pertains to performance and efficiency of Medic Grow’s Fold-8. The video examines the readings for watts at the four different settings for light intensity. I’ve also captured the amperage at its maximum and minimum levels. For this test I’ve used the P3 P4400 Kill A Watt Electricity Usage Monitor – a very common (residential/amateur) meter readily available for about $30.
Watts & Amps
Here’s a chart with readings taken over multiple times.
Pros: The light intensity knob is both easy to read and operate (assuming you have installed the light so that the controls are facing the opening of the tent). The four percentage levels (100/80/60/40) provide an optimal range for adjusting light intensity without having to change the height of the light itself. My previous two LED manufacturers do not have this feature – which requires me to make constant changes to the height of the plants and/or light during the grow cycle. Another big advantage of the percentage settings is that you can achieve on optimal DLI (Daily Light Integral) at less than 100% power; this will significantly reduce energy consumption and stress (attenuation) of the light’s bulbs over time.
Cons: None that I can identify.
PPFD (Photosynthetic Photon Flux Density)
PPFD (Photosynthetic Photon Flux Density) is the amount or intensity of PAR light that lands on a square meter each second. When factored with the hours of exposure during a day you can easily calculate the DLI, which is arguably the most important variable in managing an LED light over the course of a grow cycle. So, if you want to optimize your equipment and the results you get, you’ve got to know the PPFD that your plants at getting. Fortunately, Medic Grow publishes detailed charts of these numbers on their web site (medicgrow.com/products/fold-8-led-grow-light).
I decided to try taking some measurements on my own. The gold-standard for equipment would be the Apogee MQ-500 Full Spectrum PAR Meter for PPFD – approximately $525. I chose the close 2nd in accuracy, the <$10 iPhone app PHOTON (
https://growlightmeter.com/. It's actually a quite remarkable app with many impressive capabilities and features. Reviews clearly document its accuracy to be extremely close to the Apogee.
Here’s my video of the set-up for this process.
Before showing the two charts of my readings, a huge caveat is in order. My numbers don’t align exactly with those on the Medic Grow web site. Don’t put too much credence on my numbers. There are environmental variables that affect readings; my tent is highly reflective and the light is tight to the edges (4x4 light in a 4x4 tent). My equipment is not that sophisticated, and holding the camera at each position means that my hand and part of my body are inside the tent – that’s got to affect accuracy and consistency. Most important, I’m a total amateur at this, and my first time using this equipment. My technique needs practice – obviously the camera has to be held steady and vertically level, but I also discovered that horizontal orientation (namely where the top and bottom of the camera were facing) seem to affect the readings. Oh well.
Now, here’s the two charts from the end of the video. First, readings at 24” from each of the sixteen 1-foot squares in the 4’x4’ Gorilla Grow Tent – repeated four times, once for each power level.
Pros: two key things to note; first, the drop-off of intensity from center to corner ranges from 15-20%. This means that there is plenty of light to use the entire floor space of my 4’x4’. Second, this light is very efficient at low power levels. At 24” the 40% level and 60% level are both just a bit over optimal for the vegetative and flowering phases. Very nice. I’m going to be saving energy costs and gaining more grow space, all while achieving optimal grow cycle PPFD levels at between 300 and 440 watts.
Cons: None that I can identify.
For the second chart, I took readings at the precise center of the tent, at 3 different heights for each of the four power levels.
The conclusion I draw from this is that I’m probably going to want to keep my light fairly high up in the tent, and use lower power levels. I’ve got no problem with that. Having a tent that is 7’11” high gives me lots of flexibility.
So, now its time to throw some seeds in a pot and see what happens.