LED lighting for MMJ grow

[MannyBoy]

A Phriend here at Yahooka suggested I post some questions I asked of her to seek the collective wisdom of the group.

I have been reading about the benefits of LED lights (low heat, focused light spectrums specific to growing) so I bought a used 45 watt LED panel. The manufacturer claims it produces the equivalent of a 250 watt HID.

My questions. Is this alone a strong enough light source for seedling through harvest? Despite what the LED manufactures say, is this light spectrum sufficient, or should I supplement this with CFLs on the sides or top? Lastly, can anyone recommend a pot strain that would be best to help alleviate my spinal neck pain and migraine headaches but not put me to sleep (I know kush works, but it puts me into couch lock)?

Thanks in advance for the help. Peace of God to you all.

[Pharm Girl]

My preference is HPS......how big is the grow room MannyBoy??

If you could post up some pics of the equipment......and whatever else you have, 'cause we all like to see what's what!

What 'ja think there peoples?

[Kaminoan]

I am having great success with 5 spectrum LED's for Veg & Flower. The testing period is over! Check my photos...

[Pharm Girl]

^ Can't see photos......try uploading again, k?

[MannyBoy]

Thanks for your response PharmGirl.

I am just completing a grow cabinet that measures 6' tall 3' wide and 2' deep. I have divided the cabinet into two compartments separated by a full light proof shelf. The lower compartment for nursery and holding mother plants is 12" high and the full width and depth of the cabinet. I am thinking this is not tall enough, but I want to get as much room as possible in the top main compartment. This top compartment is 5' high and the full width and depth also.

I bought a Sunshine Systems 45 watt Glowpanel. Here is a link with a pic, some tech info, and a video.

GlowPanel 45 LED Plant Grow Light | Growing Indoors with Plant Growing Lights

[Pharm Girl]

How about ventilation.......ho w's that gonna get setup?

It's a real must.......otherwise the Bugs will come marching in........~

We'll talk ferts ltr.

Any pics......?

[MannyBoy]

I'll post pics soon. I'm almost done with the build.

Good question on ventilation. Not sure what you mean about the bugs. Maybe from the higher heat in the cabinet from the lights?

This is one of the main advantages to an LED lighting system as I understand it. There is almost no heat from the light itself. Think of the Christmas tree lights we use. Although, admittedly these are lower wattage, they are barely warm to the touch. The old big Christmas tree lights were relatively very hot.

Again, the literature from the LED companies say there is no need for head ventilation because of the miniscule heat from the lights. Anyone else out there using LEDs that can talk about the amount of heat you see in the grow area?

[SpankyMcLankey]

Unfortunately that is not the case, fresh air is a requirement for tasty nuggets regardless of temperature. As long as the room the cabinet is in gets fresh air a couple hours a day, you should be okay. Still gotta watch for bugs, especially gnats though.

[MannyBoy]

Thanks Spank and Pharm. I will ventilate. Is it good to just drill holes in the back of the cabinet near he bottom and other holes at the top (I don't want them seen for stealth reasons. If so, how many holes and what diameter should they be?

If a ventilation fan is alot better, can you suggest a size fan and placement?

Thanks for helping a new guy!

[MannyBoy]

Ok, you guys were definitely right with the need for ventilation. A hugh oversight on my part.

Just bought a 4" in-line fan that moves 90 cubic feet of air a minute ($30). This fan is supposed to by very quiet. I also bought some 4" elbows ducts with the idea of using them for a light trap (<$10).

I was thinking about somehow hanging/installing the ducting inside the cabinet toward the top. My problem with this ventilation system at this point - other than how to hang it in a study way - is how to get a 4" hole in the top of my cabinet. I don't have a scroll saw.

On the odor control side, I noticed some odor control/air fresheners at Home Depot while I was there buying the above items. They were about $80 for an inexpensive -loud- unit. Most of these systems use a HEPA filter with an activated carbon filter overlaid on top. My thought - why not DIY it with a small vacuum cleaner HEPA with some activated carbon filter material on top attached to the opening of my duct in-line fan ventilation system? Or just layered activated carbon material?

Anyone try this? Any suggestions out there?

[Pharm Girl]

As far as the size of the holes------can you go at least 4 inches?

Flexible tubing is inexpensive!

Odor control-Tried those Home-Depot everythings.....but finally went with a whole lot of Peace of Mind and got a carbon filter. And a Uvonaire.

Some hydro shops have used equipment, one needs to ask though!

[MannyBoy]

Thanks Pharm. I may have to bite the bullet and buy a real carbon filter from a hydro store, but I'll cross this bridge when I get to it.

I did some searching on this site and on some others and found some ideas about venting and odor control. One grower had a 4" exhaust tube like mine with an inline fan. I think his was attached to his HID light, but other than that it seemed to be the same. Her/his cabinet was also about the same size as mine. Getting to the point, this grower brought air in from the bottom back of the cabinet using two clothes dryer vents like you see on the outside of your house. They open and close by the force of the air on the louvers. A nice elegant solution. Two vents may be overkill - her exhaust fan may be more powerful than mine?

A different grower had directions for a DIY activated carbon filter that he built for like <$60 using 1/4" screen, regular window screen, 8" to 6" and 6" to 4" reducer pieces, and end caps. He basically made a screen tube within a tube - filling the in between space with activated carbon. Again, an interesting potentially elegant cheap solution.

More to the point of this thread, I also found a posting about a grow using a 46 watt LED. The quantity of the finished dried product was lower, but the quality, strength, and taste he judged as superior to a clone of the same female grown in a 250 watt HID. This sounds great to me I will be using a 46 watt LED panel (maybe supplemented with 36" two bulb T5 CFLs.

If anyone is interested, I can post links to either of these DIYs.

[Pharm Girl]

that DIY carbon filter thread rocks, eh??

the only problem one might have with the white dryer hise is the light might be seen due to the light colored plastic........but I found another solution that does not let light escape!

flexible metal hose-----same as a dryer hose cept it's heavy duty------i found it very affordable at home-depot in the ventilation dept.

Note to MB-Don't bite too many bullets----you'll need to visit the dentist with those 4 inch needles....~

Keep the questions and ideas coming----and when the time is right, post us up some pics, k??

[MannyBoy]

Thanks PG, I do think my OCD is kicking in, and the last time I visited the dentist he pointed several bring lights in my face and kept asking me "Is is safe?" while he drilled off half of my tooth! (If this doesn't make sense, see the movie Marathon Man it's great.

Ok, focusing on the ventilation. My air will enter at the bottom back of the cabinet through the dryer (drier?) vent. The bottom section of the cab. is 36" wide x 24" deep x 18ish" high and is covered by a shelf. I will put a 2"ish hole through here and use some PVC elbows on both sides of the shelf through the hole to make a light trap. So, light escaping from the main top part of the cab. through the dryer vent at the bottom should not be a problem. But, in the future I planned to use the bottom section as a mother chamber (sounds kind of evil!). So I guess I will get a flexi tube as you suggest for a light trap.

Do you think the 2" hole through the shelf is enough for a 90 CFM in-line fan in a 4" exhaust (with the 4" intake dryer vent) to breathe???

Second question. During the grow, do I need to have the fan run continuously or how often during a day and for what duration?

[stoneric]

Originally Posted by MannyBoy

More to the point of this thread, I also found a posting about a grow using a 46 watt LED. The quantity of the finished dried product was lower, but the quality, strength, and taste he judged as superior to a clone of the same female grown in a 250 watt HID. This sounds great to me I will be using a 46 watt LED panel (maybe supplemented with 36" two bulb T5 CFLs.

Let us know. It would be great to eliminate any heat problem while using less power. I have my doubts but would be happy to be proven wrong. Also, if you use the t5's, how will you know if the LED's actually work?

[MannyBoy]

Solid point Stoneric. Dullness of thought is one of the reasons I want to get off of my pain script oxy and onto my own homegrown.

Since this is my first grow, I am using some "bastard" seeds (seeds of questionable linage - in deference to all of you real bastards out there), and it's strictly for my medical use, no big loss if I don't get a large quantity.

I have seen several grow reports of LCD light experimenters, but they all seem to bail to HID's when it comes to bloom. I suspect this has to do with potential loss of profit.

I'll use the LCD from seedling to harvest. I will try to find my lost camera so I can begin a grow report if anyone else is interested.

[Pharm Girl]

Second question. During the grow, do I need to have the fan run continuously or how often during a day and for what duration?

both fans should run.........all da time~

[MannyBoy]

Finished the cabinet - sorry, I still cannot find the camera!. Some light leakage through joints I am filling. Also some leaks around the doors, I think I need thicker sealing material (I used 1/4" D shaped foam rubber). And much more light than I like comes through the 4" exhaust at the top of the cab. in the dark. Inside I have about 4 90 degree turns and an inline fan (90 CFM). Any ideas to help here I would love to know. Last, the fan is much louder than I anticipated. Now I am dealing with this by using a timer to only run it on off hours. Perhaps a long term solution is to use a dimmer switch to dial back the fan speed to hush the noise a bit I hope.

I germinated 10 seeds with the paper towel method. 10 popped after 48 hours all with 1" to 1 1/2" roots. Placed each into a 1" diameter round rock wool "cube". Each cube was watered with rain water I corrected to a pH of 5.8 before I added it to the cubes.

As a side note here, I really struggled with the pH of the water and the rock wool. I had purchased a brand new $25 pH meter from a local hardware store. It read around 7.0 for the straight rain water I collected. I added lemon juice to about a gallon of water checking after adding the juice of one lemon. After adding like 3 lemons worth of juice to this 1 gallon of water the pH would not fall below 6.0. I even added a little food grade vinegar. No change. I returned the meter and bought a scientifically accurate Milwaukee pH600 meter (ironically $25 even with shipping) . I checked my 1 gallon solution above - 2.8 pH! Short story, don't waste your time with a cheepo local meter. It's not cheep or accurate!

Back to the grow. I still have all 10 seedlings growing. All under just the 45 Watt LED light only. The seedlings are all approximately 1" tall with the second leaf sets just emerging.

Two questions. I read somewhere that the rock wool cubes raise the pH 1 point and the optimal pH is 5.3ish. Therefore, I am adjusting my watering water to 4.3 (with Citric acid). Right? Second, when do I think about moving the seedings to the deep water culture set up?

[Acorn#1]

my feeling on LED is that were close but not quite there, the best lamps are easily twice the cost of a top of the line HID unit and the best advantage they have is low heat output. Ill stick with HID for now but LED will probably be the light source of the near future

[MannyBoy]

Thanks Acorn#1. The reason I am doing this grow is to better understand this question. To your point, it would be better for me to be using a much higher powered LED system equivalent to the output of currently most popular HID system people out there are using to get at a true - LED vs HID answer. From what I read here it seems most are growing much larger quantities than I. So it's hard for me to do an apples-to-apples comparison.

I am using an LED light which the manufacturer claims is equivalent to a 250 watt HID light in terms of useful photosynthesis lumens. Does anyone know, is a 250 watt HID a common intensity for a 40 ft2 (5' high x4'X2') grow area? If so, I hope to provide some data from a typical albeit an LED grow.

As for the economics, the light cost me around $100 on eBay (perhaps because it didn't work well ) they go retail generally for around $125 USD. It uses 45 watts (the manufacturer says it really uses like 28 watts in reality?). So at the least (250 - 45) 205 watts per hour savings times whatever your rate of electricity plus the cost of expelling the heat plus the bulbs (LEDs last forever) and so on.

The real question: does it grow dank in sufficient quantities to justify not ponying up for the additional cash and heat signature of the HIDs? I'm not saying LED's are the answer, but I want to see for myself. Kaminoan in his post above would disagree with my neutral position.