Sorry, didn't mean to put words in your mouth SME. Looking back, I really did misquote you.

Here's an example of what I meant about big plants potentially using space less efficiently. In my experience it's easier to fill a light's whole footprint with a lot of smaller plants, like SOG, than with a few bigger plants. There are ways around it, through training or SCROG, but that usually means a longer veg time and the plant becomes much harder to move around, and mobility is essential with my non-recirculating DWC buckets.



The pic shows Matanuska Thunder F*** (week 5) in the back, Cascade Goo (week 2) in front, and Sour Kush (week 7) peeking in from the right. I rotate the plants every day, so they generally take on a round shape that gradually spreads out as the buds gain weight. You can see above how this leaves spaces open in the corners. In the past I've tried training the plants into triangle shapes to avoid this, but this still wouldn't quite fill the space when I rotated the plants, and the branches that reached farther would always end up bowing low with weight and generally causing problems.

The mention of 1.9g/w as a theoretical high yield really spurred me to start thinking about every aspect of my garden. In the near future I'm going to run 4 plants under one light to see how the increase in footprint usage (4 square plants will be easy to fill the space with), as well as the increase in medium-to-plant ratio, affect yields. I might even try autoflowers in a similar experiment.

Anyways - The FI clones for my LED grow journal are just about ready to go into 3.5gal buckets for their week long veg. Right on schedule! I'll get some pics of them up after the transplant and we'll get this journal on track.

Here are those clone pics I promised. They were transplanted into buckets 3 or 4 days ago and currently they're producing nice white roots. Once the stems start to grow more vigorously I'll begin training for a few days then move them into the flower room to start the test.

I'm really excited to see how this turns out! Updates soon!

Day 1

LED


HPS

Week 1

Everything is going as expected. The LED plant is taking up slightly less nutrient solution, and it seems to be growing just slightly more slowly. I'm noticing the biggest difference in the secondary branches at the bottom of the canopy, some of which are now about 3x longer on the HPS plant.

Week 2

The LED plant is almost keeping pace with the HPS plant. I've noticed that the HPS plant is stretching a little more but I think that both plants have about the same number of nodes. I think this might be what LED advertisers mean when they cite "more bud sites" as a selling point for their products. For a ~300w LED to keep up with a 1000w HPS is impressive though.





The plant under the SS400w has reached the edge of the light's footprint. I'm keeping it very close - about 11" - and I'm getting a little bleaching before I train new shoots down. At this close distance the light's footprint doesn't extend much past its own physical footprint. Any farther than that and the brightness of the LEDs really drops off quickly. We'll see what happens when the plant grows beyond this threshold in the coming weeks.



The HPS plant has a light all to itself after a harvest, but not for long!


Night pics:

LED


HPS

The "LED plant" sure looks like it's doing better compared to last week! How do you plan on dealing with it's size if you're already at the edges of the footprint/area covered? Since the plants are so short, I assume that you have plenty of headroom but they will get wider still too.

When you claim that the 310w of LED is "almost" keeping up with the 1000w HPS, I'm afraid that you're not telling the whole story again. As we discussed earlier, the HPS covers much more area and will therefore yield much more than 310w worth of LED could so it's apples to oranges.

Furthermore, if the 1000w HPS is stretching more than 310w LED it's more likely due to other issues, position/distance of plant from light or perhaps other environmental issues. Almost all of the CLW grow journals so far have said that the SS800w (625-ish watts LED) is about the same as a 600w HPS and we all know that a 1000w HPS will penetrate better than a 600w HPS. Unfortunately, they don't make a 300w HPS (that I know of) so it'd be harder to do a true apples to apples test with the SS400w but I have a hard time believing that a SS400w is "keeping up" with a 1000w HPS when others say that the SS800w is equal to a 600w hid.

That said, with 60w/sqft I'd expect the plants to "look" similar to the HPS, while they're small. You just can't penetrate as deep or cover as much area with the LED. Since you're keeping them short it won't be until closer to the end that the HPS will have the true advantage. You should end up with better side and lower branches on the HPS giving that plant a little more weight. That and, of course, the HPS side had/has more plants too. They both look really healthy though...

To be honest, I really do think that LED has the potential to surpass most HID lighting in the semi-near future (don't get me started again) but there are still cost factors and LED still fails that economical test too. I wish I could design a "professional series" of lights for CLW and then test those. Think they'd hire a spam-hating disabled vet for R&D?

SME, I'm sure CLW would love to let you test their products... for a price!!!

Seriously though, it would be great if you started a journal too. Then I could steal all of your good ideas and grow bigger crops!

btw I'm not claiming that a 310w LED can keep up with the total production rate of a 1000w HPS. That's why I said "this is not an apples to apples test" in my first post. However, I am observing that the LED light is supporting growth of almost the same vigor as the 1000w is within the brightest area of their footprints, despite somewhat reduced penetration.

Final judgement of performance will be determined through yield weight and quality. For now I'm just noting relative growth rates of both lights at roughly 60w/f^2. The LED plant is almost keeping up. No trickery there, just my observation.

As I understand it LEDs don't penetrate more in larger fixtures. Since they are comprised of many small lights, penetrating power is going to be roughly the same from an SS800w and SS400w, while the footprint will be different. HID lights penetrate more with larger bulbs because their single point of light becomes more brilliant, while LEDs simply use a larger number of the same bulbs to attain a larger footprint. So if the SS800w can be said to be roughly comparable to a 600w HPS, so can the SS400w as long as the w/f^2 is kept the same. Right?

Further, and I'm really just spitballing here, my understanding is that 600w HPS bulbs are more efficient than 1000w HPS bulbs because they produce more lumens per watt. That should mean that if you ran a test, with the same w/f^2, a 600w HPS should outperform a 1000w hps because there would be more lumens per square foot under the 600w.

So by that reasoning, my test is showing that the SS series of lights is less powerful than the 600w HPS since it isn't quite keeping up with a 1000w at the same wattage per square foot.

I bet you're right.

I'll be doing one when my back gets better but all I have is HID so it can't be a GFP journal. Since my back is so bad I'm designing a new system that I can manage without hurting myself. I also need a service panel upgrade so I can expand beyond 2kw. Either way, I have to change my growing style and system to be more back-friendly and that may make a different lighting scenario the best choice.

Right, since the plants are still short, 60+w/sqft is 60w/sqft, both lights are putting out more than a single plant uses so a one plant-to-one plant comparison will produce similar results until they get bigger. When penetration power and coverage become an issue the HPS will show it's muscles.

That's also correct, the SS400 and the SS800 both use the more powerful 5w diodes and that's where the penetration comes from, not from the number of diodes. So if the comparison of the SS800 being close to a 600w HPS is accurate; then the SS400 would penetrate as well as a 600w HPS but cover less area.

No, the 600w HPS lights are more efficient but they still don't penetrate nor cover as well as a 1000w HPS. If I were growing high density SOG, 600w HPS or maybe the SS800 would be a better choice than the 1000w HID. Now they even have 1500w HPS lights available but I'm not going in that direction either.