I am actually really curious now. I just googled and used JSTOR to try to find a critique of K McCree's 1972 study. Since I am not allowed to post links, do you have anything that criticizes Keith McCree's papers that isn't anecdotal evidence from a pot farmer? No offense, but I live in the world of academia where we prove things with rigorous peer-reviewed studies and hard data. Your initial post, although dismissive, did not really do a whole lot to criticize PAR, but instead deceptive marketing.

Also, my 2 cents... 1000W digital HPS ballasts have known RFI problems due to unshield-able filament vibrations. Not good for human health and delicate meters and controllers. You have to use magnetic core ballasts to avoid the problems.

I was growing cucumbers, tomatoes, and peppers, see one of my posts above. I do not believe you are actually reading what I am saying before you respond and so we are having two separate conversations. I also don't know how I will be able to do an LED grow w/o an LED light so I'm sad to say this journal is probably grinding to a halt. I already contacted a rep from CLW about returning the light.

I don't live in the world of academia, I live in the real world. They once thought that plants don't use green spectra either, now we know they do...

Show me the results that back up the PAR claims. We have several journals here from real world growers and none of the LED grows come close to what HID growers produce.

If a smaller LED grow light has as much/more PAR than larger HID (and they do) then why don't they yield as much? If PAR mattered in the real world, they would.

I can only speak to cannabis since the vast majority of indoor grow lights are used to grow cannabis. There are a few commercial growers growing lettuce, algae and a few other short crops but mostly it's cannabis and cannabis needs a lot of light. There are no smaller LED grow lights that are out producing larger HID lights, despite PAR readings, so what does that tell you about PAR?

Magnetic ballasts can interfere with some meters too but digital ballasts are more efficient. Most growers don't hang out with their ballasts.

You can do whatever you want with your light, I only suggested that you test it before making a decision. I don't work for CLW and I don't know why you think anyone is suggesting that you do an LED grow without an LED light. Perhaps it's you that's reading something that isn't being said.

We do have a few tomato and pepper grows in the forums and most of the members growing those have been happy with their LED lights, for those crops...but they actually gave the the lights a shot.


Good luck!

^The above post speaks of your credentials. The bulbs themselves vibrate the RFI which is bad for you if you water your plants or even enter the room with the lights on. Those scientist you criticize developed your field, the tools you use, and the practices you follow. You keep using the word spectra, but I highly doubt you understand what you are talking about if you don't even know who K McCree is or about JSTOR. The funny thing about anecdotal evidence is sometimes it is incorrect. You didn't even bother to read what I was growing when I told you. LET'S BE CLEAR: I gave the light a chance and after 2 weeks I can tell you that it is not worth the investment. I have had success with other cheaper lights and have a variety of HID lights and T5's on hand. I got this to test it out, review it, and let the world know if it worked. It doesn't work as well as HID lights and is very expensive. Mystery solved.

PurpleGlowGrow wrote:^The above post speaks of your credentials.

...

LET'S BE CLEAR: I gave the light a chance and after 2 weeks I can tell you that it is not worth the investment. I have had success with other cheaper lights and have a variety of HID lights and T5's on hand. I got this to test it out, review it, and let the world know if it worked. It doesn't work as well as HID lights and is very expensive. Mystery solved..

The *only* "credentials" that I've *ever* claimed to have is decades of real world experience experience which actually means something to some people.

And in the world of academia an incomplete two week test is enough to make definitive conclusions?
If you say so.

Thanks for confirming what I've said about LED grow lights for two years here. It's nice to be validated by academics...

So, should I assume that you're abandoning your GFP journal now?

You disagree with the results I've had after two weeks of veg? That the light does not cover the area the manufacturer suggested. Does this not invalidate their value proposition when pricing the light? Do you assume I don't have decades of real world experience or that I haven't worked in a university horticultural lab (#2 in the US baby!)? You're making claims that fly in the face of decades of science.

I can explain why LED lights might outperform on PAR ratings compared with HID lights w/o throwing out PAR as a useful measurement (we'd say you're throwing the baby out with the bath water here in the world of the learned.) You're criticizing decades of work without presenting your own. You haven't controlled for all of your confounding factors and haven't used statistical analysis to draw conclusions. In essence, you have an untested hypothesis and are proposing that I an others here reject a thoroughly supported piece of theory. You might as well throw out evolution and start beating your Bible.

I can point out all the logical flaws in your argument, call you a troll or a know it all, and even show you how you "aren't even wrong." But in the end, you'll still respond smuggly and suggest that I should continue with this light even though you yourself have contended that the HPS light I had in my garden before this light was a better choice.

Why are you insistent on me wasting my time and resources to discover what we both already know? I may not be ending this journal depending on how CLW responds. It may turn out I have to post here for 90 days before I can return the light. It will be the saddest experience of my life as a consumer if that happens.

I've been saying for two years that LED grow lights aren't as good or as cost effective as HID lights. I've also said, for years, that LED manufacturers overstate their coverage areas.

You, evidently, agree with me.

I already mentioned that there are a couple of theories as to why LED lights under-perform despite higher PAR readings too...

Based on results, whether or not you like it or whether you agree or disagree, PAR is a useless measurement when it comes to saying that a smaller LED grow light will do as well as a larger HID light...because they don't.

I suggested that you should fully test the light because you agreed to complete a GFP journal to test it. I can't make you finish and if you want to quit that's on you and nobody else. I have no idea what the CLW policy is on the GFP lights.

I just asked if you were abandoning your GFP journal or not because YOU said that you were returning your light immediately.

I do also suggest that you calm down and check your attitude though. You might try paragraphs to make your posts more readable too...


So, I'll ask again, are you abandoning your journal (sending the light back) or not?

My attitude's fine, buddy. I already answered your question. You're the one making wild claims and not backing them up except with a self-referential post to a short conversation you had with another person saying you weren't going to have an argument about whether or not PAR was a meaningful measurement. That isn't really telling me anything other than what you think, which you already did before you referenced your own opinion (can't ya understand why that's a problem?! It's called circular reasoning, or petitio principii) I think you're dead wrong there and there is another factor responsible for LED lights scoring high on PAR measurements, but not performing as well as expected.

Admins/moderators decide who's attitude is fine or not here.

I backed up my claims with results, you only point to a paper from 1972.

Let me go over this for you one more time:

1) LED coverage areas are justified by PAR readings. (Look at the par reading charts/specs on their websites)
2) LED to HID equivalency claims (smaller LED = larger HID) are also based on PAR measurements.

LED coverage and HID equivalency are both wrong and even you admit that they don't cover what they claim nor do as well as your HID lights. You just want to argue that PAR means something that it clearly doesn't and you want to ignore logic. If PAR was a meaningful measurement, then smaller LED grow lights would cover larger areas and yield as much as larger HID lights. They don't. You're just grasping at unproven theories to explain why they don't.


Hope that helps...