Watts needed to cover 4x8 veg table

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After building my new flower light I will have 2 chilled pucks and 2 vero cob’s that are all run at 100 w each, 400w total. Is this enough to cover a 4x8 veg table? It seems like enough watts but I’m afraid I won’t get the coverage from it only coming from 4 lights.
 
It depends on age of plants. Seedlings up to 3 weeks old I would say maybe, and only if distributed evenly with your 4 lights. For that size table, I would say a minimum of three 600 watt sodium lights, or even two 1000 watts if you could afford it. Top brand LED lights of the equivalent ratings would be cheaper and cooler. Make sure LED lights are the actual watts claimed though as they are not all rated by the actual watts consumed.
I am currently have a 2x4 grow with the equivalent of 700 watts between a 400 watt and two 150 watt sodium lights about 28" over canopy. As around week three of flower, I will hang my 1000 watt above them and remove the others. This will probably be the last grow with sodium lights, as I'm looking to purchase better LED lights for my next one. They are much cooler to operate.
 
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After building my new flower light I will have 2 chilled pucks and 2 vero cob’s that are all run at 100 w each, 400w total. Is this enough to cover a 4x8 veg table? It seems like enough watts but I’m afraid I won’t get the coverage from it only coming from 4 lights.
You have 32sq ft. If you plan to use LED, it depends on the quality of the LED. With high-efficiency you can do 25w/sq ft (704w total). Average LED might be in the 30-35w/sq ft range. (960-1120w total). Less expensive fixtures on Amazon and eBay: probably 40-50w/sq ft. (1280-1600w).

Anther factor: if you use one monolithic fixture, or many lower-watt fixtures, distributing the watts around the plants -- which let you get the light closer to the plants (less inverse-square loss), and better coverage/angles. It's more work managing more fixtures, hanging/aiming. But, you can get 22w/sq ft efficiency from a 30-35w/sq ft light. (Or, 30-35w/sq ft efficiency from a 40-50w/sq ft light source.). If you can manage more light sources, and cover the plants from more angles, closer, that makes as much difference as stepping up to more efficient light.

For comparison, T5HO (for shorter grows) should be 40w/sq ft. CMH is about 38w/sq ft (counting the ballast). HPS is usually around 60w/sq ft.

Your lights are only 12.5w/sq ft. You need at least twice as much. Maybe 3x as much. It depends on how efficient they are, how much lumen deprecation they've already experienced (and, as mentioned, how granular you can make the light for better coverage/placement).
 
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I appreciate the feedback guys but you’re both talking about flowering numbers, the 4x8 table is a veg table. You don’t need 40w / square feet to veg, those are flowering numbers. 2 1000w hps is way too much overkill for a veg table. I said they are chilled pucks(301b diodes) and 2 cob’s. 30w per square feet is flowering, not veg. 15w a square foot seems enough for VEG not flowering.
 
Ok, Yes then. But it depends on how long you are going to keep them in veg, and how many you have, how long from seed you call veg, temperature, ect.
I would say that by the end of the 4th week from seed, you you should be looking at what plants you want to keep. Then look for more watts period. After four weeks, 400 watts over a 4×8 table covered with four week old plants, are going to do nothing but stretch, even with evenly spaced lights.
I have 12 plants now, in 2 gallon pots. To the maximun outside diameter of my pots is 26"×50". I cant move the pots farther apart. They are 45 days old today. Today is day 13 of my flowering stage. One is showing female like she is a week ahead or the others. The other 11 are showing true, white pistils, so I now know they are all female. I am running one 400 watt and two 150 watt lights for a total of 700 watts. I also ran a 1000 watt Highgrow LED along side for the three males that showed before the females. They are gone now after relocating them after I decided which ones to keep and before they opened pollen sacks. (Note that the claimed 1000 watt LED fixture only draws an actual 200 wats of power acording to my Kill A Watt wall meter.)
So, that is a total of 900 actual watts in a 26"x50" space. They are 45 days old now, they are two weeks into flowering and I am probably going to put in a single 1000 watt soon.
I am saying all of this for comparrison. It mainly depends on how many, how crowded they are, and how long you plan on keeping them in veg. I will say you will need more serious power if you want real production out of that size space. Even for veg.
But they will live......
 
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JWM2

Premium Member
Supporter
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I use roughly 1/4 of the flowering watts in veg. In a 4x4 space I flower with 680w of quantum board LEDs. I have a 260w quantum board setup in my veg rack and have it turned down to 125w for efficiency. I veg in a 2x4 space. But that’s me.
 
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I use roughly 1/4 of the flowering watts in veg. In a 4x4 space I flower with 680w of quantum board LEDs. I have a 260w quantum board setup in my veg rack and have it turned down to 125w for efficiency. I veg in a 2x4 space. But that’s me.
Thankf you for the reply. I am thinking 12-15w per sqaure foot is more than enough for veg, I was just worried I would not have the best spread because it's only coming from 4 pucks, but I have decided to put my chilled pucks along with 2 or 3 samsung f strips above it and that will completely cover the entire table with a much better spread than I have right now with my hps, and I will only be using 400-500w max compares to 750 from the hps.
 
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Stick a pic up of your new lights and the footprint they produce set at half the height of your tent, you'll know if it will cover what you need or not.
 
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After building my new flower light I will have 2 chilled pucks and 2 vero cob’s that are all run at 100 w each, 400w total. Is this enough to cover a 4x8 veg table? It seems like enough watts but I’m afraid I won’t get the coverage from it only coming from 4 lights.
I think the power is enough for veg room. but i doubt they cannot cover the plant perfectly.
 
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I think the power is enough for veg room. but i doubt they cannot cover the plant perfectly.
That's exactly what i am thinking so I am going to put my 2 chilled pucks to cover at least a 4x2 or 3x3 and the rest of the table I am going to buy Samsung f strips so I will probably have around 450-500w if I need but it will be much more evenly distributed than 2 pucks and 2 cob's
 

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