Grow lights

[djwintz]

I have 2 plants that I have growing indoors. I just ordered this led light. Are they a good light?
Mars Hydro TSL 2000 Full Spectrum Dimmable 300W LED Grow Light

 

[Phytoplankton]

Yes, that’s a very serviceable light. Never owned one, but many on this forum use that brand. Should work just fine for two plants. Best of luck on your grow.

 

[TorturedSoul]

It's okay. Depends on the size of the space you are trying to cover with it (same as every other grow light).

 

[djwintz]

Should be okay for coverage I'm thinking as it's only 2 plants. I've been using a HPS Cool tube set up but thought I'd give the LED's a try. Thanks for the replies.

 

[TorturedSoul]

What size/shape space will you be illuminating with it? It's advertised as being adequate (for the flower phase) for a space that is 2'x4'. There are some PAR maps available on the manufacturer's web page for the product, that show its output, when hung 12" above the top of the canopy, at various output settings. At 75%, it appears to produce an excellent output in the middle 1'x3' area (in an enclosed 2'x4' space with reflective walls), but not so much in the 6" border around the perimeter. Increasing the output to 100% does increase the amount of light in that perimeter area, somewhat - but at the cost of producing too much light in that 1'x3' central area (unless you'll be adding a good amount of supplemental CO₂ to the space - which, assuming the temperature is high enough, will enable the plants to process more light-energy).

Perhaps running the product at 100% output, but adjusting it to hang at 14" or even 16" above the top of the plant canopy would give you a more even coverage in a 2'x4' area, decreasing the amount of light that hits the plant surfaces in that middle region, while increasing the amount that falls on the portions of the plants that are close to the edges. But this is merely speculation on my part; Mars Hydro has chosen to only post PAR maps for a 12" height. It might be worthwhile to send an email, asking if they have the output at a height of 14" and 16". One assumes that, if they do, they'll send it to you upon request.

 

[djwintz]

Thanks. I was going to call them tomorrow and have a chat.

 

[TorturedSoul]

I forgot to mention that my above comments were somewhat situational, as I was thinking about the flowering phase of photoperiodic plants instead of autoflowering ones (or the growth phase). You could get by with less light output for either of those things because, presumably, you would be running the light for ≥18 hours per day instead of 12.

And it wasn't referring to whatever the minimum you could get by with and still manage to get "a harvest," either. I wanted to mention that, for clarification. ~1,000 PPFD seems like a good "ideal" amount, for average ambient carbon dioxide levels. Or maybe for the levels of 20 years ago . I guess, at least in theory, plants should be able to process slightly more light-energy, and at a slightly warmer temperature, than they could 30 years ago. But I cannot quantify that statement worth actual numbers.

 

[Sativa1970]

I forgot to mention that my above comments were somewhat situational, as I was thinking about the flowering phase of photoperiodic plants instead of autoflowering ones (or the growth phase). You could get by with less light output for either of those things because, presumably, you would be running the light for ≥18 hours per day instead of 12.

And it wasn't referring to whatever the minimum you could get by with and still manage to get "a harvest," either. I wanted to mention that, for clarification. ~1,000 PPFD seems like a good "ideal" amount, for average ambient carbon dioxide levels. Or maybe for the levels of 20 years ago . I guess, at least in theory, plants should be able to process slightly more light-energy, and at a slightly warmer temperature, than they could 30 years ago. But I cannot quantify that statement worth actual numbers.

I looked into this years ago and found it a bit unnerving but interesting.

The increase in CO2 over the last 100 years is inconsequential, at least for plant growth that is. A 100 PPM increase. The target for plant optimization is adding 1500PPM over current outdoor levels. Most homes are around +900PPM and sleeping in a 100 square foot room with standard ventilation for 8 hours pushes it to 1500PPM. EPA standard is stay below 2000PPM.

Bonus trivia; 1 gallon of plant converted H2O into O2 = 1 hour of a human at rest converting O2 into CO2.