Lighting

[Thunderfirst]

I am using five 65w LED grow lights approximately 8 to 10 inches above plants in a 2 1/2 by 3 1/2 ft grow room. Is this enough light for successful flowering?

[JohnEmad]

Hi Thunderfist,
What make of lights are they? Are they true 65 Watt? At first look you appear to have enough light.

[Thunderfirst]

Hello JohnEmad,
Thank you for responding. They are Great Value Plant Light LED BR Reflector. They are claimed to 8w usage / 65w equivalent. I had vegged them with just one of these lights at 1ft distance but read to flower properly I would need alot more wattage. They were shifted to 12/12 light schedule 12-21-2019. Installed the four other lights today, 1-4-2019 and lowered them to between 8 to 10 inches. Watching carefully for the stretch to occur and try to make adjustments accordingly.

[JohnEmad]

Ahh! so at 8W/light you are using 40 W total. Most experienced growers will tell you that 30W/sq ft is needed to flower properly so your nearly 9 sq ft would need 270W if the space is full of plants. Seems like you have enough light for seedling stage and very early veg. After that you will need more wattage to have better results.

welcome to the forum btw.

[Mrblu]

I have read that generally 50watt of real power from the wall (not equivalent) per square foot is a good rule of thumb, high end lighting you can get away with 35w/sf

[JohnEmad]

I am running about 45W/sf of better quality lighting for my 2x4 tent so I agree Mrblu. There are so many articles out there stating anywhere from 30 to 60W but too much will have diminishing returns.

[Thunderfirst]

Are you saying the 8w grow light stated to have 65w equivalent is only giving out 8w each for a total of 40w for the area and not 65w/ 325w total.

[JohnEmad]

Hi Thunderfist, What we are saying is the true wattage drawn at the plugin is the way to determine what you will need to flower your plants. There are some manufacturers who state their lights are 1000W equivalent but only draw 150W actual power.
You could keep adding more of the same lights but there are other alternatives that may make more sense.
Can you send a picture of your setup? and the lights you are using? that could help in seeing your situation.

[gbauto]

Thunderfirst, welcome to confusing marketing.
Growing plants requires photons(just a unit of measurement) of light to grow plants. The confusion starts when we try to estimate how many photons of light a fixture can produce from each watt of electricity consumed. The efficiency of a light source has a huge impact on producing light(photon/watt)-this is where using power density(watts/sq ft) can help you estimate if you have enough intensity to grow good flower. For lower efficiency lights like CFL's, at least 50 w/sq ft. HID fixture(HPS,MH,CMH) 40-50 w/sq ft. Top-tier led's like a QB can hit that same light level at 30 w/sq ft.

[Thunderfirst]

An 8w grow light sustained the entire area for 10wks of veg. and grew well. Maybe I'm misguided in thinking 5 times that amount would be sufficient for flowering. Would adding more of the same seem unreasonable?

[FunkyButtLovin]

Can you share some pics of your setup?

[JohnEmad]

This could help as well.

https://www.growweedeasy.com/cannabis-grow-lights

[Mrblu]

It takes far less light to veg. Light is food, when they flower they get very hungry, much much more is needed.

[Thunderfirst]

Will try tomorrow. Right now they are 4hrs in dark. Won't see them again for almost nine hrs. Thanks for the responses.

[Thunderfirst]

Hope these help explain my delima. Some of these have already started flowering under one LED light. I'm hoping 5 of these LEDs is sufficient. Time will tell. 🤔

[herbgrower]

It will start to flower as the natural plant instinct but I think what everyone is trying to say and I would like to add is that you will not get potential yields as you would under calculated lighting setup. Along the fact that the plants are in 10 weeks old, the ideal vegetative growth isn't there. The stems are thin and leggy. They have less leaves and overall there are bud sites but there is not much area for it to expand. We will have to see how much the plant stretches and how the leaf growth goes. I think what I want to say is you will have buds but the yield won't be much. You have used good capacity pots and you are also not in SoG method so the growth should be bushy and somewhat fatten. Just my opinion, not an expert one!

If you want to calculate lighting:

http://cannaversity.com/calculators/lighting.php

[Thunderfirst]

Thank you. They leggy one maybe a sativa as I really know any of the strains as they were randomly gathered from very good med grade. This is my first grow experimenting and with good advice may achieve a starting point from which to advance.

[Thunderfirst]

Don't know any of the strains. All have been topped. Trying to keep small plants due to limited space. Maybe next grow will be 1 or 2 plants of certified strains with traits I desire.

[Thunderfirst]

Previous problem was lighting.
I'm researching LED light for 28" by 40" grow room. Any suggestions? I'm thinking I should not fill the entire area with light system. How much space should be around light system? I know LEDs don't emit alot of heat.

[FunkyButtLovin]

How much are you wanting to spend and is heat a major factor?

Unfortunately, efficient leds aren't cheap and cheap leds aren't efficient. You could go HID which is cheap and works well but not the most efficient and produces a fair amount of heat. Most of the leds that don't create much heat are low power or expensive. A watt used is a watt used and about the same amount of heat is going to be produced as a by product, LEDs tend to spread that heat over a much larger area than a single bulb of an HID. Changing my HID reflector and bumping up 200w yesterday affected the temp under the lamp (went down) but the temp of the grow room stayed the same. If you don't have deep pockets (I do not) or aren't willing/wanting to dedicate a lot of money to this, it becomes pretty hard to find lots of performance on a budget.

I use HID because I wanted to have plenty of light to flower several square feet and didn't have the money to buy nice QB or strip based LED lights big enough to do what I wanted. $150 will buy you a 100w of QB or a 1000w HPS. I have 400w and 600w ballasts and can run 150/250/400/600 watt bulbs depending on how much light I need or if things get too warm and swap between spectrums for veg/flower.

[Spidermite]

You need more light. For 4ft by 4ft I use 1000 watts actual draw from the wall. But that's just me. For $130 or so a viperspectrum 450watt (212 actual watts) would do good.

[JDU]

@ Spidermite I love the new signature 👍

[Spidermite]

Thanks

[Thunderfirst]

Problem solved?
Friend is having a Viperspectra 1000w shipped to me. Special at $109.00. Spidermite suggested a 450. Hope this isn't too much. Lol 😜. Someone said there is no such thing as overkill when it comes to light. Wish me luck.

[Spidermite]

You should be good with that light.

[Thunderfirst]

Thanks Spidermite.
It's sure nice to have good BUDS to go with good BUDS. Lol😜. My friend grew a primo outdoor crop so I think he's using me as a test on indoor. Fine w/ me.