How many LED’s for 3 or 4 plants?

[Finnicki]

We bought a 3x3x6’ tent. We run a 600 wt
LED. We have sprouted one Amnesia Auto
Fem seed so far. Bought those seeds because of a shorter height of plants. Wondering how many I could grow with one light? Two lights? Filter and fan are in tent, but can be moved outside if need be. Thanks. Happy Growing.

 

[Old Salt]

Is that 600W what they advertised, or is it what it draws from the wall?

 

[Finnicki]

Advertised. Bloomspect LED. 60 lights, 10 per light. Auto flower will bloom no matter the lighting schedule, correct?

 

[Old Salt]

The light probably draws 100-150W from the wall. This is important, because manufacturers keep it low to maximize the light's efficiency and lifespan.

You need 30W / sq ft or 300W / m^2 from a top of the line LED. A light such as yours, you'd probably need 40-45W/sq ft.
with 9sq ft, that's 360 - 400W, from the wall.

I learned this the hard way. My first light was an 1800W dimmable COB. I thought it would be more than plenty for a 2' X 4' tent, so I got the dimmable version. At full power, it only drew 315W from the wall. It was not enough for my 2' X 4' tent.

The above was written before I looked up your light. Here are the specifications from the Amazon Canadian website:
Specifications:
Model Number: B600
LED Power: 600W (60x10W)
LED Types: dual Epiled/Bridgelux chips
Avg. Power Draw: 110V:132W±3%; 220V:129W±3%
HPS Replacement: 250W HPS/MH
Dimensions: 11.8" x 7.9" x2.6"
Grow area at 20" Height: 2.5x2.5ft
Flower area at 16" Height: 2x2ft
Input Voltage: AC 100-240V
Frequency: 50-60Hz

You would need at least three of these lights for your tent. Most of us LED users have our lights about 12" above the canopy during flower. Cannabis is a light lover. At this distance from your plants, you'd need four of them, as the coverage area decreases as the light gets closer to the canopy.

I'm going to suggest a visit to Mars Hydro for their TSW-2000. This one light will be enough for your tent. They are currently on sale for 15% off. This is very rare from them. Usually our discount is only 3%. What will it cost? About $210 USD. You may even be able to get a further discount from @SmokeSara, their representative in this forum.

I have one of these in a 40" X 40" tent, the Mars Hydro 3' X 3'. Here is what the plant looked like five minutes ago:

Granddaddy Purple Under Mars Hydro TSW-2000​

This light draws 310W, and as you can see, will do the job of lighting your tent very well.

EDIT: The plant is 36" from side to side.

 

[Mars Hydro]

Hi Finn, according to your explaination, the light should be only around 100~150w, There are real 10w chips in the market, but it will be super expensive, and if it is true 10w chip, the light might be around 500USD or more. Otherwise, they will lose money.

So that light should not fit your space. You can try to check out our TSW 2000, it covers 4x4 space during veg and 3x3 during flowering, though it is only 300w, but can replace a real 600w HPS and help you grow great result. The PPE is high, that is why it can be so efficient.
We have many growers using this light, and getting great result, I am sure you will also.
Now it is the best timing, since we are having Black friday sales, the light is only a little over 200USD, you will love it.

Mars Hydro Black Friday Sales 15% off 2019.jpg

• Mars Hydro
• Nov 19, 2019

Mars Hydro TSW 2000

• Mars Hydro
• Sep 19, 2019

 

[Finnicki]

I worry about burning leaves with a strong light.

 

[Old Salt]

You don't need to worry about that when using the TSW-2000s. You can pull the power plug from one of the boards to have only half the light for early growth. You can also turn down the adjustable driver to do the same thing. You can also save power using these methods. As seedlings, disconnect one of the LED boards, turn down the remaining driver, and drop the light to about 12" (30cm) above the seedlings. You can use a light meter app on a smart phone to measure the light at the canopy keeping it at the ideal level for your stage of growth.