LED Light height in grow tent

[ToughCall]

Thank you, mad John, that point about DLI, I've read some in past articles, but always went with "this" size light for a 4x4 tent. DLI is what I need to understand based on my lights, so I'll check into more it.

Good stuff!

[Farmer Geddon]

I'm hoping to find a 'That'll do' mid range setting that lets me do grow after grow without having to adjust anything.

[MadJohn]

Thank you, mad John, that point about DLI, I've read some in past articles, but always went with "this" size light for a 4x4 tent. DLI is what I need to understand based on my lights, so I'll check into more it.

Good stuff!

You're welcome.

Look up "Photone" on Android or IOS store it will measure it trivially for you. Load the app, hold the phone horizontally under the light at the canopy top and you're done. On IOS it's about 97-98% accurate and on Android it's about 91%. It will give you an accurate enough reading to base your grow on. It's not perfect but it's close enough to not matter and doesn't cost you $700.

MJ

[V8]

I have 2 lights in my 4x4 which are both Spider Farmer, but they're different wattage. SF2000 which is 200 Watts, the other is SF4000 which is 450 Watts.

I start out at 36" from the tops - Seedling to midveg, then in late veg I lower it to 24" and in flower I start at 22" then down to 18". With earlier grows I was able to go lower than 18" but I'd watch for curling of leaves and possible burn marks.

When used my SF4000 in my 3x3 i used the max distanse they recomented for the stage. So if they say veg is 22-30 i would veg 30 inches away. I think I maxed out at 20inches in late flower with the SF4000. Dimmed to 80% or so.

Why do you need 2 lights for your 4x4? The SF4000 should be enough?

V8

[Mac]

When used my SF4000 in my 3x3 i used the max distanse they recomented for the stage. So if they say veg is 22-30 i would veg 30 inches away. I think I maxed out at 20inches in late flower with the SF4000. Dimmed to 80% or so.

Why do you need 2 lights for your 4x4? The SF4000 should be enough?

V8

multiple points of light > single point

[ToughCall]

When used my SF4000 in my 3x3 i used the max distanse they recomented for the stage. So if they say veg is 22-30 i would veg 30 inches away. I think I maxed out at 20inches in late flower with the SF4000. Dimmed to 80% or so.

Why do you need 2 lights for your 4x4? The SF4000 should be enough?

V8

With my first three grows, I only had the one SF4000 for the 4x4. I picked up a 2nd tent (3x5) and also bought 3 SF2000 lights for it (2 length wise, each end, 3rd in the middle width wise), thinking they might be best at 600 watts. 2 ended up covering the 3x5 just fine, so instead of returning the 3rd SF2000, I added it to the 4x4 as it appeared to provide better coverage at their recommended heights with less shadowing on the perimeter leaves etc.. I never used par meters then, still don't, but I just downloaded the Photone app based off mad John's mentioning of the app. I'd like to see if these LEDs should be at the highest point in the tent while still being as effective as can be. Plus, I like to tinker, which can be a downside. For instance, I used UV lighting with my last three grows and learned from each session. But with the additional work of setting up and ensuring that I am not cooking the leaves and not seeing a worthwhile difference, I scrapped it. YMMV & IMHO of course.

[Tommy stoner]

I've been growing with LED lights for a few years now. In my experience keeping the light about 14 inches from the canopy works
well for me. Weather it's 300w or 1000w 14 inches is close enough during veg and flower.

[V8]

I love wall to wall coverage. Fun thing. When I had my SF4000 I used a little over 400w. When I upgraded to the SE5000 with a better spread I use less W (370) yet still better coverage.

I will imagine both your lights will cover the 4x4 pretty good and the diode spacing is more compact then lets say a SE7000 bar light. So hanging the lights higher then normal would be smart. Following the Spiderfarmer user manual is just a waste of time IMO.

V8

[GEORGE]

I love wall to wall coverage. Fun thing. When I had my SF4000 I used a little over 400w. When I upgraded to the SE5000 with a better spread I use less W (370) yet still better coverage.

I will imagine both your lights will cover the 4x4 pretty good and the diode spacing is more compact then lets say a SE7000 bar light. So hanging the lights higher then normal would be smart. Following the Spiderfarmer user manual is just a waste of time IMO.

V8

Same thing here for me Barney. I can only use 260W of my 500W light. If I use any more, I get plant burn.

[ToughCall]

This is all interesting. Some growers keeping LEDs close enough to the tops as long as there is no burn, and others mounting straight at the roof bars. I'm guessing no one has any complaints with their yields using low or high LED positioning, otherwise there would be a sticky on it. Which is good!

I am considering raising the LEDs to the ceiling, as I often raise the LEDs (those nice pulley straps) when feeding and plant maintenance. I'm going to use that Photone APP to see what the results are with my LEDs at ceiling height, leaving space (of course) between the LED's drivers and actual ceiling material.

Has anyone experienced burn on the reflective tent material from hot drivers being too close?

I believe from the Spider Farmer PAR reviews and several others, hold PAR ratings high enough and recall 800 PAR was more than enough to bring quality flower, 1000 PAR or higher was recommended for sealed CO2 environments. Everything is strain dependent, but most of these stains have been bred to handle a number of tolerances, light being one of them.

Growth stage: Avg PAR recommended
Seedling / Clone 100 – 300
Veg 250 - 500
Flower 500 - 1050

Fascinating stuff!