Feasibility Question

[hamstring]

Hello IC Community

So I just pulled down my last winter indoor harvest today. Getting ready spring and outdoor season. I was seriously considering adding LED fixture to my grow space for Veg only. It would cut down on heat and electrical cost for the spring/summer months.

I dont want to pull my air cooled HID fixture from the room because I want to keep it for flowering and my space is so small it would be a pain in the ass to move in and out. I would like to mount a LED fixture large enough to cover a 40" x 40" grow area under my HID fixture.

After accounting for HID fixture height, pot and plant height, air space between
LED fixture and HID fixture.

My LED fixture would be 38-40" above the plant canopy. Is this a possibility or am I just to close to the plants to make this work in the configuration I have called out?

Refer to my drawing below. I couldn't even get my wife to hang my art project on the refrigerator.

 

[Three Berries]

My veg tent is 3x3x60" tall and plenty big for me. I'm using about 150w max though and 3.5 gal pots. Towards the end the light was all the way up.

 

[goingrey]

It will be fine. 40" is maybe even too far away (depends on what light you've got of course).

 

[hamstring]

My veg tent is 3x3x60" tall and plenty big for me. I'm using about 150w max though and 3.5 gal pots. Towards the end the light was all the way up.

That sounds like I'm a bit too close. Can you dim your LED?

 

[hamstring]

It will be fine. 40" is maybe even too far away (depends on what light you've got of course).

Thanks for the reply.

I guess thats my dilemma. I am hoping to cover the whole 40" x 40" area because I have to sometimes sex plants before going outdoors and I may have up to 15 or more 1 gal pots in the small space. My 600watt MH bulb covers the area nicely when pulled most of the way up.

Buying a LED fixture large enough to cover that area and still be able to get that close is what worries me. I guess the answer is I may have to sacrifice something.

 

[goingrey]

Thanks for the reply.

I guess thats my dilemma. I am hoping to cover the whole 40" x 40" area because I have to sometimes sex plants before going outdoors and I may have up to 15 or more 1 gal pots in the small space. My 600watt MH bulb covers the area nicely when pulled most of the way up.

Buying a LED fixture large enough to cover that area and still be able to get that close is what worries me. I guess the answer is I may have to sacrifice something.

Here's for example the "industry standard" Gavita 1700e PPFD chart 4ft x 4ft area.

Optimal PPFD for veg would be about 700-900 PPFD. Seems like pretty perfect for the entire area at a 30" distance. Ok your area is slightly smaller, but you get the idea...

 

[Three Berries]

That sounds like I'm a bit too close. Can you dim your LED?

I can cut out 50w of light so it's 100/150. It is too small for the stretch in flower.

 

[hamstring]

Going Gray, I am past going, I am grey.

Thank you sir that helps a lot. I will look at some of the offerings from Mars.

 

[Three Berries]

I also have a smaller tent. I use to have a 100w in the 5' one but it wouldn't get hot enough in the winter so I got a yet smaller 3x3x3' tent for the 100w dimmable and seedlings.