Is this grow light setup enough to do anything?

Do-it-yourself projects such as greenhouse or shadehouse builds and related topics.
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cerclerouge
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Is this grow light setup enough to do anything?

Post by cerclerouge »

I'm in NYC.

I have these 4 light strips mounted into a shelving unit. Four 10W, "250W Equivalent" T5's. (the amazon link for specifics: https://www.amazon.com/gp/product/B0814L4XPL ) The lower shelf is about 22" below the lights. Some of the cacti will be in taller pots, putting them closer to the lights. They are brighter than they look in this photo. If you're facing this shelf, 10 feet to the right is a south facing window.

Is this suitable for any/some/most cacti? What if I doubled up on the same lights (8 strips instead of 4?). Or do I need to get a more powerful system, period? Any thoughts? Thanks!


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greenknight
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Re: Is this grow light setup enough to do anything?

Post by greenknight »

Looks like they mean the entire set together is equivalent to 250 watts of incandescent. I think this would be adequate for forest cacti, for desert cacti doubling up on them might be good.
Spence :mrgreen:
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One Windowsill
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Re: Is this grow light setup enough to do anything?

Post by One Windowsill »

Are you growing columnar cacti or globular cacti?
cerclerouge
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Re: Is this grow light setup enough to do anything?

Post by cerclerouge »

One Windowsill wrote: Sat Jun 19, 2021 8:13 pm Are you growing columnar cacti or globular cacti?
Potentially both. Appreciate any input.
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One Windowsill
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Re: Is this grow light setup enough to do anything?

Post by One Windowsill »

For globular cacti I would raise the shelf much closer to the light. Think of where you want the light to hit the plant. Globular cacti will catch the light on their sides from the LEDs to each side as well as the top being illuminated from above. If I have got the dimensions right you have over 200w of LED per metre squared, which should be enough.

Columnar cacti would have a large area of the side of the plant not illuminated at all well with the light positioned above. I would have two units at opposite sides and allow the tops just to be illuminated by reflection.

In both cases you should surround the plants on all sides (including above) with reflective plastic (preferably the high-quality diamond-patterned type) to make the most of the light you have. A small fan to move the air about, or to bring it in to the enclosure if you have completely surrounded them, is essential for the health of the plants. A standard quiet 4 inch computer fan would be ideal. Is that one I see in the lower left hand of the picture?
cerclerouge
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Re: Is this grow light setup enough to do anything?

Post by cerclerouge »

Thanks for the explanation. That fan is actually tiny, a 40mm, I'm using it in a tropical terrarium, but yes, I will absolutely include a larger fan in this setup.

The other issue is that, at that south facing window, 10 feet to the right, are my tropical plants along with a humidifier. So I'm trying to grow plants from opposite climates in the same living room. I'm usually able to keep the cactus area in the 40% humidity range which is probably the best I can hope for during a NYC summer.

ALSO I'm trying to AVOID having it look like a professional grow operation, which I part of the reason I chose these lights to begin with. They blend in with the shelves and you can't see them unless you're below them. Anyway, ignoring that, what if I add some lights on the bottom shelf level too, the same level that the pots would be sitting on, maybe facing diagonally up towards the cactus. Think that would help at all? Thanks again for all the input.
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greenknight
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Re: Is this grow light setup enough to do anything?

Post by greenknight »

Agreed that this would be enough light if it were all concentrated on the growing area, but these are wide-beam lamps (160 degree beam angle according to the specs) so the light spreads out rapidly. Having the lamps lower would make a big difference, but I know from your earlier posts that you already have a couple of Totem Pole cacti that need this much height (fortunately, they're slow-growing). Reflective panels all around would work, obviously, but then you couldn't see the cacti! The white wall behind helps some, but there's still a lot of light escaping.

Lights shining upward wouldn't be good (light the pots more than the plants), but lights to the side would be fine. If you could figure a way to mount a vertical panel on each end, with light strips on those, that would work really well.
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One Windowsill
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Re: Is this grow light setup enough to do anything?

Post by One Windowsill »

Perhaps also enclose your tropical humid plants with white plastic (rather than silver that might give passersby ideas) so the humidity builds up around them and does not spread so much. It will also keep the draughts down that many such plants hate. 40% humidity should be fine for all cacti as long as they get a nice draught.

I agree with greenknight's points.

Unfortunately, if you don't surround the plants with reflection it will look like an unprofessional grow operation. :lol: Could you turn it into a cupboard? Growing houseplants with lights is getting very common now.
cerclerouge
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Re: Is this grow light setup enough to do anything?

Post by cerclerouge »

Thanks guys. Since it seems I'm at least in the realm of grow light acceptability, I think I'll swap my current lights out for these, which will sit in the same shelf system: https://www.amazon.com/dp/B082ZKJZP1 These will give me 1400W equivalent, are longer (so I can fit more cacti of course), and have reflectors on each light. Hopefully this will help!
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mikethecactusguy
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Re: Is this grow light setup enough to do anything?

Post by mikethecactusguy »

Nothing matters other than how much light actual reaches the plants. You need a minimum of 10,000 lumens at the plant surface. Everything else is B.S. Get a light meter and check. Either get more lights or move them closer to the plants. Wattage means nothing. Its all marketing.
Lumens at plant surface is all you need to know. And yes, it can be that simple.
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