Basement grow tent and Samsung F-series LED strips - Orchid Board

turbosloth10 · #1 04-14-2020, 03:10 PM

Hey everyone,

I set up a basement grow tent/greenhouse about a month ago, and finally just got the real lights set up after my heat sink tape came in from China (previously I just had a 4 ft LED shop light from my garage). I'm posting this here partially to document for people who may want to do something similar, and also to get input from more experienced folks.

So, I purchased one of those cheapy 5x5 greenhouse tents from Amazon and set it up in the corner of my unfinished basement. The location seems perfect, as I have a hose spigot in that corner as well as the basement sump to drain any water I spill on the ground. The shelves are pretty terrible, but I zip tied some fence material to the shelves to make them functional, as well as behind the shelves to hang mounted plants.

For lights, I was inspired by Naoki's blog (orchidborealis), the LEDGardener blog, as well as the "recreational plant" forums. As of 2020, it seems like the way to go is the Samsung LED strips, of which there are several different choices. I went with the F-series strips(LT-F562B, 2ft strips), which I think are a good balance of efficiency, output, and price. I combined these strips with 3/4" Al C-channel for a heat sink, wago connectors, and 18mm heat sink tape from Amazon. The strips are powered by a Meanwell constant voltage driver, with a good amount of headroom for a max of 6 strips (~12 ft total) at their nominal output. I won't get too much into the design, choosing a driver, etc, as the blogs I mentioned above go into some serious detail about all that.

Needless to say, these lights are a massive step up from an LED shop light. Approximately double the efficiency, much smaller, and very adjustable. Interestingly, despite the much smaller emitting surface compared to the shop light, it seems like the coverage is much more even with the strips.

And now where I am looking for advice. Unfortunately i don't have a real PAR meter to measure light levels, and I don't see myself spending $500 on one any time soon. AFAIK, cell phone light meter apps aren't particularly accurate (especially for LED's), but it's all I have right now. I am running a single row of strips above the shelf. With the lights 18" above the shelves, I am getting about 500-600fc at the shelf, and anywhere from 700-1000fc at plant level, depending on the height of the plant or where the mount is hung. The back wall also has a single strip hung over some fence material, with similar light levels. Currently, the strips are being underdriven. My multimeter shows 22.8 volts, and around 800mA per 2 ft strip (nominal is 1100ma). Per the data sheet, this should be somewhere between 4100 and 4600 lumens of output per strip (so 8200-9200 lumens per 4 ft light). Total power draw at the wall (for 3 strips) is 63w.

Extrapolating from actual measurements other people have done of similar lights,I think I am in the ballpark of appropriate light levels, probably on the high end. I am growing plants with low-moderate light requirements (angraecums, highland dendrobiums, masdevallias, bulbophyllums). I've thrown around the idea of renting an Apogee PAR meter to get some real light level readings, but I'll see what y'all say and see how the plants respond to the current light levels.

-Bill

DirtyCoconuts · #2 04-14-2020, 04:49 PM

i don't know anything about indoor growing but i really dig the setup structurally and i might try to copy something similar for outdoor growing in the future.

very nicely built.

i don't know how damp or dry your basement is but you might want to look into visqueen or vapor barrier (think thick painters drop cloth but plastic) to hang around the greenhouse if you need to up or contain the humidity.

fishmom · #3 04-14-2020, 05:02 PM

For what it is worth, you can get a PAR meter for quite a bit less than $500--more like $150--on amazon or several other growers supply houses.

That said, have you asked you orchid society members? You might be able to borrow or rent one that way. I know the societies are not meeting right now, but if there is a newsletter or Facebook page, you might be able to contact folks.

turbosloth10 · #4 04-14-2020, 05:21 PM

Dirtycoconuts, the cover of the greenhouse is actually some sort of plastic with woven cloth embedded in it, which contains the humidity really well. My basement stays around 50-60% RH, and adding the greenhouse didn't seem to change that appreciably at all. California is fairly dry, so I don't think humidity will be a huge issue for the structure of the house as long as it stays contained in the tent. The inside of the greenhouse stays 80%+ RH, and spikes into the 90's after watering. We will see if mold or fungus becomes an issue, but I hope it won't as air movement is pretty good with just a small table fan.

fishmom, your right I could totally buy the standalone Apogee PAR sensor and use it with my digital multimeter for I think $180. I'll ask around the society when we start meeting again, I know there are several people who grow under LED's. Unfortunately, I have only been to a few meetings and don't know them very well.

DirtyCoconuts · #5 04-14-2020, 06:17 PM

very cool, that sounds ideal.

Dorchid · #6 04-15-2020, 10:38 AM

Nice setup!

farley101 · #7 07-04-2020, 03:07 PM

This is a great setup! I'm looking to do something similar this winter for my plants since it's not economical to keep the house at 70+ degrees and 60+% humidity in the winter.

The lighting was the one spot I was unsure of how to handle. I have a lot of Cattleyas so will need a lot of light to keep them happy. I've been looking at a lot of lights but I'll keep in mind the DIY option as well as that may be the most flexible. Thanks for sharing!

Carebear2 · #8 07-05-2020, 07:04 AM

Hey turbo, love what you have done, your lights look amazing, I certainly haven't got the patience to assemble them myself with the heatsink, driver, wiring and light strips.
I can understand wanting to get the light perfect but you never will, even if you used a light meter and set it all up perfect according to each plants needs I am sure you will still end up adjusting and moving plants around based on the colour of their leaves. I have dendrobiums that are supposed to be high light loving plants but every time I try to acclimatise them to more light their leaves turn red and I need to move them out of the light so it's more important to see what your plants can handle and go from there than using a light meter to set it up as you think it should be.

Younger plants can't handle as much as mature plants.

Also your tent is losing about 30% of your light compared to a light reflective tent. I personally prefer the tent you have gone for but they are designed to let sun light through, in your setup you will need to use 30% more electricity but minor really since your lights are the most efficient you can have and using all 6 will most likely be too much for the size.

turbosloth10 · #9 07-05-2020, 08:04 PM

Quote:

Originally Posted by Carebear2

Hey turbo, love what you have done, your lights look amazing, I certainly haven't got the patience to assemble them myself with the heatsink, driver, wiring and light strips.
I can understand wanting to get the light perfect but you never will, even if you used a light meter and set it all up perfect according to each plants needs I am sure you will still end up adjusting and moving plants around based on the colour of their leaves. I have dendrobiums that are supposed to be high light loving plants but every time I try to acclimatise them to more light their leaves turn red and I need to move them out of the light so it's more important to see what your plants can handle and go from there than using a light meter to set it up as you think it should be.

Younger plants can't handle as much as mature plants.

Also your tent is losing about 30% of your light compared to a light reflective tent. I personally prefer the tent you have gone for but they are designed to let sun light through, in your setup you will need to use 30% more electricity but minor really since your lights are the most efficient you can have and using all 6 will most likely be too much for the size.

I stressed about the light level for a bit but ultimately just let it ride and am glad I did. Running those strips at essentially their nominal output (about 23w per 2ft strip if I remember right) seems about the right amount of light. I have two zones, light is either 18" or around 24" depending on the plant light requirements. I'm getting great growth and have definitely moved some plants around based on how the leaves look, but ultimately everything is growing great. I've since mounted a bunch of plants and hung them on the wall behind the lights, and have bought made a bunch of quarantine acquisitions. I only have 6 ft of lights so far so lots of room to grow.

I also added a mistking, an ultrasonic humidifier, and an inline fan to bring some outside air in, otherwise there is very little temperature differential in the basement day to night. Everything is controlled by SmartThings switches, works pretty well! I can go away for a few days without watering. I could probably do longer, but would have to do some testing to make sure nothing is being over or underwatered.

Ultimately I am really pleased with the project so far. I will post some pics and more details one of these days for anyone who is interested.

Farley, you could definitely crank out enough light for your Cattleyas with a similar setup, I mean people grow tomatos and "tomatos" with these lights. Or if you have the space and need more lights, COB led's could be an option for mo powa.

farley101 · #10 07-05-2020, 11:33 PM

Haha, "tomatoes" wink wink.

I spent a few hours reading about DIY lighting and watched a few videos as well so I feel like I have a better handle on it. Still working on getting strips matched up with drivers and best practices for setting all that up but I'll get there. I plan to put together a small setup for the tiny greenhouse I have all my seedlings in. Seems like a good way to practice and replace the nasty burple lights I'm currently using!

I'm thinking COBs are probably overkill for this use, though maybe I could add one to the system for just the vandas. Hmm, decisions... 😅