Kinda stupid question...

Hello guys, I have few small scale grows under my belt, first cfl then couple of MH/HPS and now I'm thinking to try some LED equipment to reduce heat and power consumption.
I have just one question, when someone on RIU compare gpw between HID and LED do they compare LED wattage on the wall or declared chip wattage?
Thanks!

LED wattage at the wall.
The rest is bullshit. If your looking at lights that call themselves "2000w grow light" that are 300 true watts then I wouldn't even waste your time buying that crap.
Cheap LEDs require the same wattage as HID lighting.
Good LEDs that can save you a 3rd on heat or electricity cost a lot of money.
Don't rush into this, learn more.

If your prime concern is electricity cost then CMH or Quantum boards (good LEDs) would be where I would be researching.
If heat is your major issue I would just find a way to properly set up your grow room. There is no substitute for proper environment and air exchange.

Edit, with good LEDs the declared wattage is the same as the wattage at the wall, except maybe for driver inefficiencies. Timber growlight and horticultural lighting group are good companies if in the US.

What size grow space do you want to light up?

Thx for quick response! I have 240x120 grow tent and two 1000W HPS which are bringing me about 1.2 - 1.4 kg per grow depending on strain. Lately I was researching LED panels which have 550 true wats and claim to outdone 1k HPS but I have hard time believing that and they are somewhat expensive to just go and buy them without thoroughly researching them.

grasshoper031 said:

Thx for quick response! I have 240x120 grow tent and two 1000W HPS which are bringing me about 1.2 - 1.4 kg per grow depending on strain. Lately I was researching LED panels which have 550 true wats and claim to outdone 1k HPS but I have hard time believing that and they are somewhat expensive to just go and buy them without thoroughly researching them.

Click to expand...

Im guessing your looking at something like the HLG550 then.
I think it would be fair to say equal to around 850w than 1000w. I know a few people have taken issue with that claim before, but I also know others have been happy with them over 5x5 spaces and they are certainly enough for 4x4 space or two of them in your 2.4mx1.2m tent would give good results.

I had the same flower tent, I swapped out 3x600w hps and covered one half of my tent with 2x260w Quantum boards , pretty much same output as the HLG550. I was more than happy with the swap. I built my own cob light over the other half, around 700w.
Both sides (I run perpetually so harvest one half at a time) pulled me 2lb per run dry. So 4lb out of the whole 2.4x1.2m if I were harvesting all at once. Best would of been 4.4lb dry.

If your looking at the HLG550 then I would suggest looking at the HLG600 on growers lights.com , it gives you a bit more wattage using the same diodes but its a fair bit cheaper than the HLG550.

Are you in Europe? Just wondering because of the Meter and Kilogram units of measure.