300W LED vs. 400W HID Demonstration

Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

Setting Sun said:
It's a "Massey" 4" fan. They carry them at lots of X-marts, but it's usually a seasonal item. You can find lots of them on ebay too.

It's probably not enough for a tent any bigger than mine though. For a bigger tent, I'd go with a 6" or 9" Lakewood fan, or any fan that pivots so that you can orient it vertically.

I may add a couple more fans to my tents as it gets thicker in there, but the center fan pointing up stays through the whole grow.

I think it stresses plants to blow them around too much, but blowing up from below, if you get the fan size/speed right, works really well.

I arrange the plants far enough apart to allow a good breeze to hit the light, but close enough so that a few fan leaves catch some of the breeze also. When the breeze hits a few of the lower fan leaves from below, it deflects and gently flutters the whole plant.

I play with circulation fan position a lot, because the devil's in the details, and blowing up through the center of the canopy towards the radiant heat source is my favorite setup.
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i want 2 of ur 4" fans under every 2 of my 4 plants:thumb: i think i would be better off spreading lower strength fans to every 2 plants then 1 bigger fan that stronger to 4 plants with it being in the middle.. what u think about that idea?
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

Ya know folks, I've been following these post 'cause I too have been curious about LEDs, but now yall got intrested in hempy....also I went with the Lowe's 'Dynamite' because I read it here, and my plants look the best so far...now, the fan setup, little details add up

Thanks to all for your effort and time...

NCDude
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

I would position the plants so that you can create "holes" big enough in the foliage for some of the breeze to penetrate up and hit the lights, but have the plants close enough so that a few of the outer lower fan leaves catch some breeze also.

If you needed to, you could prune away blocking fan leaves to help create those wind tunnels up to the light. Your canopy temps will drop significantly.

These fans are single-speed, but since they're only 4", they're not too strong. With multi-speed fans, I've only used the lowest setting.

I'd rather add multiple low-speed fans than a larger fan. You get better coverage, just like with lights, and you reduce your risk of failure, which isn't usually a disaster with a circulation fan failure, but it's not good either.
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

Setting Sun said:
I would position the plants so that you can create "holes" big enough in the foliage for some of the breeze to penetrate up and hit the lights, but have the plants close enough so that a few of the outer lower fan leaves catch some breeze also.

If you needed to, you could prune away blocking fan leaves to help create those wind tunnels up to the light. Your canopy temps will drop significantly.

These fans are single-speed, but since they're only 4", they're not too strong. With multi-speed fans, I've only used the lowest setting.

I'd rather add multiple low-speed fans than a larger fan. You get better coverage, just like with lights, and you reduce your risk of failure, which isn't usually a disaster with a circulation fan failure, but it's not good either.
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ya i agree, ive notice somthing the other day with my plants, all the back plants are allot smaller buds them the front ones, the light is the same we the back ones even have some reflective material, i am thinking its because the lack of air blowing on them? since their so big and dense the fan the in front of the room cant hit the back ones so good, they should still be getting good air though because my exhaust and filter in right by them so it has to be a breeze, shit maybe the exhaust is sucking the air to qiuck around them and hurting them? dont know if that makes sense, but some how it does in my lit mind:lot-o-toke:
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

It could have to do with them not getting as much air circulation as the other plants. I don't think that your exhaust is affecting them.

Leaves in stiller air have a thicker boundary layer and don't work as well as leaves that have a breeze breaking up or reducing the layer of still air around them, but it doesn't take a real strong breeze to disrupt the boundary layer around the leaves, just some air movement.
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

Setting Sun said:
It could have to do with them not getting as much air circulation as the other plants. I don't think that your exhaust is affecting them.

Leaves in stiller air have a thicker boundary layer and don't work as well as leaves that have a breeze breaking up or reducing the layer of still air around them, but it doesn't take a real strong breeze to disrupt the boundary layer around the leaves, just some air movement.
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ya that might be it, lack of a breeze, the canopy is beyond dense. i have no way to get better air back their without spending money on a wall mount fan. who knows it could have just been those plants were more stressed or just not as good, the bad thing is that 2 of the back ones are the purple DM and 1 OC+.
i still have a OC+ up front, but no purple ones, so i will have to give it a try again and see how it works for me, but i have this grow to also give me a heads up. i really like the red bottle and its growing so fat ass buds for me but i hate that they dont put Cal in it, i really dont want to spend the money nor time adding cal/mag all the time. it them dudes would add cal it would be a kick ass grow fert for our buds. either way i will suck it up and use the red again.
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

wow nice work SS got through page 24 since i just found this. going to catch up on the rest tomorrow. cant wait to see how it turns out +reps
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

dogsnova said:
SS you got to remember the effect of inverse square law... A 400w HPS HID light one foot off the canopy gives aprox 55,000 lumens.... Put that same bulb two feet off the canopy and now were talkin' aprox 15,000 lumens if that...

That's the thing with HID lighting...... IMO in order for this side by side to be fair... The HID bulb must be kept aprox one foot off the canopy.... If not the HID lighting will be at big disadvantage and it's going get it's ass handed to it...lol

The heat coming from the HID light is by default...... It's not the lights fault...

We as the growers have to remove the heat which in turn lets us/you put the HID light much closer to the top of the canopy..
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I have to disagree. I think it *is* the HID light's fault that it requires air-cooling to be used in temperatures where an LED light with roughly equal wattage doesn't, but yeah, it is what it is.

Trust me there was a time not so long ago 1989 (lol) when we as growers didn't have air cooled hoods.. Hell I remember when there wasn't even glass for the hoods...
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I'm 54, I believe you ;).

The exact reason that air cooled hoods are for sale today is because growers saw the effects of having HID bulbs one foot (or closer) off the canopy..
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That's not why I bought an air-cooled hood. I bought one because it was the only way I could run a 400w HID at this time of year. The ability to drop it down low is a great side benefit, but without the improved temp management, distance to canopy would be a moot point.

It would be interesting to know what percentage of HID hoods in use are air-cooled.

I agree that keeping the HID light up higher than necessary in an attempt to equalize things would put it at a disadvantage.

Would a non-AC HID light get it's ass handed to it in this comparison?

Just my 2 cents...:thumb:
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worth a lot more than 2 cents to me, because I know I tend to over-think things, so I appreciate other perspectives.

thanks dog ;)



bmarduk said:
Optimize both lamps and equalize both environments, lamps are apples and oranges [hence the comparison] conditions should be apples to apples to minimize variability. If the HID needs more cooling to create an equal environment, note it and move on, but don't let the climate vary between tents. The differences between these fixtures such as price, spectrum, heat load, performance, etc. are all factors in the decision making process with regards to a purchase. Performance can't be properly compared if the test rooms are significantly different in conditions.

b:surf:
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makes much sense, thank you bel ;)
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

Setting Sun said:
Would a non-AC HID light get it's ass handed to it in this comparison?
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Vertically..... Not a chance...

Horizontally.... IMO yes if it has to be kept 20" off the canopy.. You will only be getting aprox 20,000 lumens with a 400w HPS 20' off the canopy..

You could get 28,000 lumens from a 250w HPS kept 12' off the canopy...
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

Here is a good little read...

For (artificial) light, there is a law that always applies known as the Inverse Square Law. It states that light diminishes exponentially in energy as the distance is increased from the source.

A good example is that you might be getting 1000 PAR Watts at 4" from your light source, but that would change to 250 PAR Watts at double the distance (8"). This law makes it EXTREMELY important for indoor plant growers to get their light source as close as possible to their plants. The amount of light your plant receives is directly related to it's yield/flower density.

The problem: Indoor lamps used for plant cultivation (HID - High Intensity Discharge) give off large amounts of heat, to such a degree that they could cause damage to the plant if put too close.

Indoors, there is an optimum distance/height between the plants and the light source. This distance fully illuminates the whole canopy with direct light from the source, but is as close as possible to the plants for maximum lumen intensity. This will be called the OLH, for Optimum Lamp Height.

Ultimately, to get the best light efficiency from your lamp, you want it at the OLH at all costs.
Overall, it would be beneficial for one to add glass if needed to keep their lamp at the OLH, due to the all-powerful Inverse Square Law; moving light farther away will greatly reduce the amount of energy being emitted and is reaching your plants (Light intensity is directly related to yield and flower density).

Almost all glass offered today for insertion in air-cooled lamp hoods is tempered glass, which is regular glass with low amounts of impurities. If one was looking for the most efficient glass for their hood, quartz glass will allow the transmission of UV-B, but is not made specifically for light hoods.

And also remember, that if you have a rectangular garden, it is important to position the longest side of the reflector parallel to the shortest side of your garden.

There are a number of factors which play a part in the temperature radiated from your bulb, watts, hood design and air circulation for example.

A simple method of testing for temperature is to use the back of your hand; if its too hot for your hand, its too hot for your plants. Good ventilation is the key to getting your light closer to the garden.

Recommended typical OLH distances:
400w HPS: 1 foot
600w HPS: 1.5 foot
1000w HPS: 2 foot
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

dogsnova said:
Here is a good little read...

A simple method of testing for temperature is to use the back of your hand; if its too hot for your hand, its too hot for your plants. Good ventilation is the key to getting your light closer to the garden.

Recommended typical OLH distances:
400w HPS: 1 foot
600w HPS: 1.5 foot
1000w HPS: 2 foot
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This light discussion is just what i was about to search the forum for. Thanks dogsnova.

SS, loving the action.
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

IB what is hot shoot NPS for the mites? Some of us newbies dont know all the abbreviations yet LOL

thanks to IB i raided a few home depots for a bunch of DM

one question i have is how do you flushing the TRF at the end of flowering? Will the DM effect the taste or anything ?

learning lots thanks guys
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

Dexter4Morgan said:
IB what is hot shoot NPS for the mites? Some of us newbies dont know all the abbreviations yet LOL

thanks to IB i raided a few home depots for a bunch of DM

one question i have is how do you flushing the TRF at the end of flowering? Will the DM effect the taste or anything ?

learning lots thanks guys
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NPS No Pest Strip like Gator said, will destroy mites and all other bugs, save my grows a few times. get them at Homedepot.

from what ive been told you do need to flush TRF because they put off such low ppm's, i have no idea about the taste, since i haven't harvest yet, put others said it was good
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

NCDude said:
Ya know folks, I've been following these post 'cause I too have been curious about LEDs, but now yall got intrested in hempy....also I went with the Lowe's 'Dynamite' because I read it here, and my plants look the best so far...now, the fan setup, little details add up

Thanks to all for your effort and time...

NCDude
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Glad you're finding useful info!

There are some very knowledgeable and experienced growers sharing their stuff in this thread, so we all benefit ;).

I'm fascinated by cannabis, and it's cultivation, so you know I'm havin' a good time ;).

thank you, NCDude, knowing that this grow is encouraging and helpful to others is what keeps me going.

and being an attention-whore, of course, but that's secondary, lol
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

dogsnova said:
Vertically..... Not a chance...
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I thought about it, but a vertical 400w bulb would light-stress the plants in a 32x32" tent, and it's not a mainstream method of growing (yet), which is important to this grow.

A 250w vertical HID would do well, but again, vertical isn't mainstream, although Mr. Gator may be helping to put a dent in that ;).

Horizontally.... IMO yes if it has to be kept 20" off the canopy.. You will only be getting aprox 20,000 lumens with a 400w HPS 20' off the canopy..

You could get 28,000 lumens from a 250w HPS kept 12' off the canopy...
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I'm still amazed that this LED light works so well at 20".

thanks for your feedback dog. I know you've grown with both HID and LED in the 300-400w range, and that you're a straight-shooter, so I value your input.

Have you ever used the Gavita-type reflectorized HID bulbs that you use bare and horizontally? I believe they only come in 250 and 400w.
 
Re: 420 Cannasumer Reports Competition - GrowLEDHydro 300w LED vs. 400w HID

dogsnova said:
Here is a good little read...
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good stuff dog, thank you

And also remember, that if you have a rectangular garden, it is important to position the longest side of the reflector parallel to the shortest side of your garden.
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not always possible because of space constraints, but you see a lot of reflectors oriented the wrong way even when there is room to do it the right way.

How about LED panels like the Spectra 300? Should they be oriented with the longest side parallel to the short side of the grow space? My tents are square, so doesn't matter there, but how does that 120 degree lens work as far as orienting the light most efficiently in a rectangular space?

400w HPS: 1 foot
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:thumb:
 
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