Some light spectrum and set up questions.

[MJTECH]

Toker1 , Not an argument, just a different perspective, money can be an issue. I only use LEDs, I have had minor problems at one time, nothing a soldering iron can not handle. Bulb replacement, if you actually need to replace an LED, is just soldering. Of course my LEDS were expensive, not Mars, Meizhi, I would prefer Blackdog, just way to expensive. I will admit that HID is much cheaper, and the technology is getting better. I am an enthusiast when it comes to LEDs, I am planning to build one at 600 watts. Just letting people know there are options out there and that investment is cheap or expensive.

While I prefer LED's what bugs me about a lot of the is how manufacturers lie about their wattage, for example the Meizhi 1200 watt lamp only pulls 420 watts at what they call 110 volts, two problems with that, 420 watts is not 1200 watts and in the U.S. we use 120/240 VAC not 110/220 VAC.

[MJTECH]

They do lie, they do so by omission, they talk about equivalent, not actual. The market is very misleading. With that said, we are going into par and not lumen, someone also mentioned measurement by umols. Honestly, what I do understand falls under spectrum. not lumens, by which we define the measurement of perceived light. Even though "blurple" has been considered unattractive, by means is not inefficient.

I believe it is all about tossing out big numbers hoping no one knows better, I refer to them a Chinese watts.

And yes PAR is the correct measurement for comparing grow lamps.

[Toker1]

Oh. Ok, got it. Thought that was a little funky. Saw a comma and didn’t realize it was a period. I was wondering what that power factor was. Lol. Makes sense now.
But think about the amount of heat that comes off the 420w actual draw. No where near 1200w. So that’s how you know the par output is a BS measurement. The BTU’s don’t lie.

[Obi-Wan]

The equivalent wattage listed by “most” LED manufacturers is the maximum wattage if each chip was driven at 100%. Most Chinese manufacturers won’t drive their chips over 40%, which is why you will find 300 watt fixtures that pull 135-140 watts from the wall. The important thing to understand about LED lights is that how hard the chip is driven is proportional to the longevity of the fixture. Any LED driven over 40% risks high failure rates. The higher you drive a particular led chip, the closer you get to Hid wattage, thus losing the benefit of using LEDs. The benefit of a 10 watt chip over a 3 watt chip is that you can get higher wattage from the fixture without driving the chip too hard, but it will pull more wattage. COB’s allow you to drive the chip at a higher rate without sacrificing the lifetime of the chip or using more wattage, but they are more expensive. The manufacturers are not telling outright lies when they say a fixture with 100-3 watt chips is a 300 watt light, their just not telling you that they are only driving each chip at 40% so they can say that it will last for 50,000 hours.

[Toker1]

Here is some good info on light availability recommendations for LED. DrPhoton really breaks it down to specific u-mols.
https://forum.growweedeasy.com/forum...-on-led-lights

[Toker1]

Here is one place where he discusses the cheap bluple LED’s being inefficient. He goes on to say there are efficient gas discharge LEDs that can compare to HID. But the thousands of dollars you pay for that type of efficiency is hard to make back up over the LED’s life cycle.

https://forum.growweedeasy.com/forum/growing-community/190892-how-to-compare-grow-lights

[MmmHmmml3]

Here is some good info on light availability recommendations for LED. DrPhoton really breaks it down to specific u-mols.
https://forum.growweedeasy.com/forum...-on-led-lights

Thanks, those are very helpful. The light arrives today or tomorrow. Planted seeds wednesday at 10pm, Friday morning they definitely were coming thru, but not there yet. When I got home saturday 11pm they were all fully sprouted up.

This is the worst part because I can't help, but to keep checking. They all have two sets of leaves since last night and still look about the same today. Put them 18" under the 40w led. The new light arrives tomorrow, not really sure if I should even use it until another 3 or 4 days.