Confusion regarding lighting and "watts" the right amount

[LadyToker]

I am an inexperienced grower. I am only growing a max of 4 plants, and that is only if I am lucky and keep my damn hands off of them

I have 300+ watts in lights, close to the growing stage of the container.. I am using a mylar blanket cover and the lights are reflecting off of a huge bathroom mirror, only a foot away and the lights are all around the plants. Is this enough lighting?

I see these Pro 900 LED Four 14 Watt Hydroponic Plant Hydro Grow Light Panels14w Tri Band. They are only 14 watt so I would guess that you would need several.

I am so confused

 

[netstatmen]

hello there, for optimum lumens, you should have 30 (as minimum) to 60 (max) watts per square foot.

Here is the formula:

Square footage (length × width) of your room x 20 (wattage)
= The watts needed

hope this helps

 

[netstatmen]

an important advice, if you choose LED grow lights, is to have in mind that there are many cheap LED grow lights and their real wattage is almost a half of what manufacturer claims.

also you should pick a light that has full spectrum (the more bands the better for your plants) if you have just one room (and not a veg room and a flowering room)

 

[Exemplarisch]

hello there, for optimum lumens, you should have 30 (as minimum) to 60 (max) watts per square foot.

Here is the formula:

Square footage (length × width) of your room x 20 (wattage)
= The watts needed

hope this helps

Lumens are for humans, plants don't use lumens.

you can you from 100Watt m2 to 1000Watt m2(3 square feet)

 

[Cultivator]

300w over 4 plants isnt alot but u'll get some weed. 600w hps would be better if its an option.

 

[Perfect Sun LED]

Mirrors are one of the worse reflectors. I've done lux reading tests on several materials, and I was sort of surprised that my own hand, human skin reflected light better than a mirror.

300 watts of what kind of light?

 

[canabinerd]

300 watts of incandescents will only allow you to watch your plants whither, while 300 watts of hps will probably allow you to grow around half a pound at the high end.

I think you would be better to think about how much yield you want and let that guide your decision.

 

[netstatmen]

Lumens are for humans, plants don't use lumens.

you can you from 100Watt m2 to 1000Watt m2(3 square feet)

that is right, sorry my subconscious betrayed me, i was talking about watts (just substituted the word lumens for watts), lumens are for humans, PAR is for plants.

 

[KarlJay]

There's more to the game than just wattage. I have 6 600 Watt HPS lights. I do this because it allows me to hit the plants at different angles and I can move the shorter plants to one side and put the lights closer to the plant.

There's BIG issues about getting the light to the whole plant. I've put lights on the side and down the center in order to get light to the lower parts of the plants.

HPS lights have a best range of about 18" from the light and 18" down from there. So the top 18" gets the best light, the rest get what they can.

LEDs have their advantages for heat and power, but you need to look at getting light where it needs to be at a power level that works for the plant.

The light loses a lot of it's power as you move away from it.

One solution is to have many smaller lights rather than fewer large lights.

You can also mix lights, you can add cheap CFL lights to hit certain areas.

One other way to address this is to have short/wide plants using LST.

I got 3 pounds from 10 plants on my 1st run. My 2nd run I got 3 pounds from 27 plants. The difference was LST, lighting, and floor space.

As you can see, proper planning makes a HUGE difference. Getting lights to ALL of the plant is a BIG factor.

LEDs are light and stay cool, they should come out with one that has a bunch of small panels on goose neck adapters so you can move them around to where they need to be. Having all/most of your light come from 1 flat panel is not the best idea.