[foomar]

Trying to design a good comparative side by side test with a 126 watt penetrator against an HPS lightsource and its not obvious how to do it and have any usefull results at the end.

Plant choice is easy , C99x that many will be familiar with , identical soil/nutes ect and the only difference being the light.

Can equalise canopy temperature and humidity with a bit of ductwork.

Every picture taken under daylight bulbs and colour balanced.

Run the test twice back to back exactly the same way.

Feel a realistic comparison would be against a 250 sodium rather than a 400 but undecided.

Two questions are how many plants in what footprint would be fair , should a cooltube be used on the hps or should both be kept at 12 inches.

The spec suggests approximate coverage area of 2′ x 3′ at 12″ above your canopy so should the 250 be the same , room or box size not an issue for me but space is premium or fixed for many.


A cooltube allows to get within six inches i find on a 250 , however few people use them.

Led angle is 60 deg , would reforming the HPS reflector to the same angle help to compare.

Canopy height and penetration is another issue , my choice finish bushy at 24 - 30 inches , maybe something taller to test the penetration claims.

Keen to set this up and document in tedious detail but only if its more than just some pretty pictures and no data at the end of it , any suggestions would be very welcome.

Lots of local real world interest in a proper test as well , ebay shite has got leds a bad rep round here but riseing leccy costs and smart meters means a lot of people are considering paying for something that demonstrably works beyond veg.

[apollonio]

hey foomar!

i think a fair test would be against a 400W since that's what is said on the website (and, IMO they should change that to "comparable to a 250W"). I think the HPS should be cooled if you need it to operate on it's maximum potencial, since the LED light is operating in it's maximum too.

As for the angle, don't think you should botter with it also. To me, a fair test would be done using the regular settings growers do when using their HPS systems. The height should not be the same since the lights aren't the same.. you should try to get the best out of the two in any ways necessary. And making that using same soil, nutes and clones from the same strain.

Making a test using a 250W HPS would be intresting to see if the LEDs would "destroy it" as claimed before. They aren't getting the results, not even close... But there are a few tests going with a single unit that could change that.. lets see!

Peace and a great new year to all!!

Personally, aside from what LED girl has already said about the lights abilities, I think the fairest test would be conducted under 126 led vs 150w hps or 144 watts of 2' t5s. I'm not hating on Leds, if they can produce 1 gram per watt of quality smoke then they have a suitable application among hobby growers. They just arent magic mj growing light engines, which seemingly they need to be claimed as in order for people to get over the high initial sticker price...

At any rate if you read the sticky thread up top, you'll see you are prohibited from doing any comparative tests, so its kinda a moot point, interesting but moot.

[WeedIsGod]

Originally Posted by 02020

Personally, aside from what LED girl has already said about the lights abilities, I think the fairest test would be conducted under 126 led vs 150w hps or 144 watts of 2' t5s. I'm not hating on Leds, if they can produce 1 gram per watt of quality smoke then they have a suitable application among hobby growers. They just arent magic mj growing light engines, which seemingly they need to be claimed as in order for people to get over the high initial sticker price...

At any rate if you read the sticky thread up top, you'll see you are prohibited from doing any comparative tests, so its kinda a moot point, interesting but moot.

Shenanigans. One of her panels must simply be run up against or inquired about in every thread. If a thread does not have a motive to further the knowledge surrounding her LED grow panels (and her LED grow panels alone) then it has no place here. LEDGirl bought this forum, it belongs to her and it is dedicated to her business, not LED or mj growing in general.


Have we seen a sog or scrog comparison yet?

[foomar]

At any rate if you read the sticky thread up top, you'll see you are prohibited from doing any comparative tests

As a new thread , this was read by ledgirl and found suitable to post.

This unit cost a significant amount of money to me and i need to justify its purchase , not least to several local growers who have seen it and are unconvinced of its capability to do very much at all apart from look like a gay disco light.

They will not take leds seriously unless they see figures which quantify results into g/watt or a true HPS/Led ratio or g/KWH in some cases.

Will forget about space and use each light source to the best concensus of setup for each type to maximise bud.

Still favour a 250 , if it is comparable to this in the real world i will be very happy and junk the hps for more.

Second thoughts on plant choice and height , given the four foot penetration maybe it would be a fairer test to pop 50 of a cross i have documented well and fill both test cells with the identifiable and consistent tall pheno once sexed.

Few people i know do any proper training and run most things untopped from seed , none venture online.

Would like to see how a genetic blue colours up under leds as well.

[foomar]

Been checking lots of 250 w HPS grows on several forums and there is a huge variation of floorspace used equivalent to anywhere between 20 and 100 watts/ft.

manufacturer states

Approximate Coverage Area of 2′ x 3′ at 12″ above your Canopy

so

Intend to run against a 250 in the same size box , no cooltube as rarely used in reality.
Whatever height they need for vertical growth untopped , 12 inch burn radius on the 250 and 12 or less pending pattern test on the led array.


Some of the claims i have seen online for leds are quite simply unbelievable and defy the laws of physics and are an essay in deception and misdirection.
Resellers of similar but 120 degree arrays claim equivalence to 600 and even 1000 watt HPS lights useing strange comparison factors and unquantified claims.

Did plenty of research first and the claims for this unit are amongst the most conservative and restrained , i understand the demands of marketing but feel a 250 comparison would be a fair and credible one and relevant to a lot of small grows.

The only concern i have with the unit is the value of haveing 24 IR leds takeing a good percentage of the total output , may swap them out after the test as the case will have to be modded then for its planned final placement.

Should have a borrowed photon flux meter in a couple of weeks , only a handheld but gives the total PAR flux in umol thingies but unfortunately not the full spectral distribution , working on that one as the equipment is not cheap but exists now within my old industry and favours are owed.

Running on its side illuminateing a six by three foot veg box for a week nearly , florescents still in place so its pretty bright in there , overkill but want the unit burnt in , if electronics fail they will do it in the first few weeks in my experience and as MTBF statistics show.

Plants look healthy but reckon they were already at their max growth at very high purp cfl levels , have given up trying to colour balance the dreadfull images taken under leds and after decades of looking at shades of green they convey little information to me .

Over xmas had a chance to run the led past a number of growers , older people seem very interested in non canna use for light hour extension and cactii as keen gardeners.
The price raised no concern , some garden centres would charge that for a simple florescent rack , they are interested by the low operating costs and long life and especially the safe low " bulb " temperature compared to a percieved fire risk with HPS.

Any comments welcome , if you see anything which could compromise validity please point it out or suggest improvements , better now than after the event.

[Hammerhead]

The only issue I have is all of the people I know including myself use Cooltubes. This might be because we all use 600 hps or larger in smaller areas and need to keep them cool. But where talking about at least 50 people that use them within the people I know.

[LEDGirl]

Originally Posted by foomar

Did plenty of research first and the claims for this unit are amongst the most conservative and restrained , i understand the demands of marketing but feel a 250 comparison would be a fair and credible one and relevant to a lot of small grows.

We just posted a new sticky recently that talks about our equivalency and how it was determined. It might make for some fun reading if you'd like to check it out, but I think a 250W comparison grow is just as good as anything else. All that really matters in the end is gram per watt, so it's not all that important what you compare it against.

Originally Posted by foomar

The only concern i have with the unit is the value of haveing 24 IR leds takeing a good percentage of the total output , may swap them out after the test as the case will have to be modded then for its planned final placement.

The 126W does not have 24 IR LED's... I think you counted a few too many lol.

Originally Posted by foomar

Should have a borrowed photon flux meter in a couple of weeks , only a handheld but gives the total PAR flux in umol thingies but unfortunately not the full spectral distribution , working on that one as the equipment is not cheap but exists now within my old industry and favours are owed.

We list the photon flux values, lumens, and lux on our website. Just click on any page for our LED Grow Lights (63W, 126W, 318W), and the data is right there for you. It was done on a professional machine in a completely dark environment except for our lights.

[apollonio]

Originally Posted by Hammerhead

The only issue I have is all of the people I know including myself use Cooltubes. This might be because we all use 600 hps or larger in smaller areas and need to keep them cool. But where talking about at least 50 people that use them within the people I know.

I think that if Foomar lives in a place where is cooler and he doesn't need to use a cooltube to keep the room at around 27C (80F) at max, i don't see a problem. But if he can't keep the temps low, he should use a cooltube or any kind of aircooled reflector. High temps can be achieved with a single 250W depending on certain factors and the plants won't yield as good.

The same for the LEDs, if he lives in a place that is too cold, he should warm up the room.

My point is, they both should be operated in their greatest conditions to be fair.

LEDGirl,

Do you know of any grow report of your single unit (126W) giving a yield of 250g? That would be what a 250W HPS can do (sometimes more).

I have seen in another forum that a few growers are pulling great yields with LEDs, sometimes more then 2g/W in a SOG style grow with high yielding strains such as Chronic. PM me for the links.

Your math makes sence, as do your research.. i understand why you say your 126W will yield as good as a 400W, but there is any documented grow using your lights giving 400g? That would be very cool!

Anyways, good luck with your test foomar! I'll be watching for sure!

[blynx]

Originally Posted by LEDGirl

All that really matters in the end is gram per watt, so it's not all that important what you compare it against.

You mean that if you run a 600hps and get .5gpw, ie 300g = you end up with almost 11 ounces and you replace that 600hps with a 126w led fixture and you get 1gpw, ie 126g = 4.5oz you've done better?

Even if you replace the 600 with two 126w and get 252g, ie 1gpw, your overall yield is still down from a single 600hps.