New light decision help

dufiwon

Well-Known Member
I'm getting new lights soon need help choosing.
I am growing in a cabinet 36"w x 18"d x 42"t. Right now I have two 90 watt ufo led tri-band with the red, blue, and orange spectrum I removed the glass lens. With a 96 watt 2 foot 4 bulb t5 with two 3000k and two 6500k bulbs. S&p td-100 with a cheap carbon filter off amazon. It has two round 4" darkroom lovers as intakes.

The candidates are:
Two 100 watt hans panel $420 shipped
Two Mars II 400 watt $384 shipped
Two Old Mars hydro 300 watt for 125 shipped
Apollo 12 from 400 watt for 254 + shipping
Building a cob light

I was thinking of building a cob light but I don't know enough about them.
Could i run two cree cob off a single driver?
Would it be better than the others?
Should I run 3070 or 3590?
Use 4 cheaper cob instead of 2 better cob's?

I am replacing my carbon filter also. Is the can 33 worth $125 plus flange?
Any advice is appreciated thanks
 
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az2000

Well-Known Member
Why are you considering LED? Do you have electricity expense or heat that you're trying to reduce? If not, T5HO would be a better choice for 42" tall than the Mars-Hydro and Apollo. You'll have to run them at 50-60w/sq ft to get similar results as T5HO at 40-45w/ sq ft. And, you'll have a serviceable fixture which uses commoditized parts, can be sold on Craigslist five years from now, etc.

I don't see any reason to buy Mars-Hydro or similar (Apollo) when you have to run HID-like watts through it. Buy a HID and you'll have a life-long fixture too.

If you're really fighting heat or electrical expense, the Hans panel would be good. Or, LED lightbulbs work well in a shorter space like that..
 

az2000

Well-Known Member
A t5ho don't fit. I am already using a 2ft t5 4 bulb.
You could supplement that fixture with the lightbulbs I linked to. They work well. I use them at 20-30w/sq ft.

You have 4.5 sq ft. I assume you have a 2-tube T5HO. That's 48 watts. and covers 1 to 1.2 sq ft at 40-45w/sq ft.

So, you have 3-3.3 sq ft to light. That's like 4 18w Cree PAR38 flood lights (two on each side of the T5). That would cost about $80 for the bulbs, $20 for the sockets and things. If you wanted more flexibility, coverage, etc., you could do 8 Cree 9.5w bulbs, or GE 10w BrightStiks (although, these haven't been proven yet.).

I know the lightbulbs seem low-tech. But, they really work. See my plant as of yesterday. That was vegged at 21w/sq ft in a 48" tall space. I switched to 23w/sq ft the day earlier. And, am stepping up to 25 now, 14 days into 12/12.

The inexpensive epi-whatever fixtures will work. But, you'll have to run more watts/sq ft than they are spec'ed (advertised) for. It's not as bad in a shorter space than people who try to grow in taller 7' spaces.

But, the lightbulbs have longer warranties (10 years for Cree). After you invest the energy of mounts and reflectors, you have a commoditized source of light. Just run down to the nearest retail store and buy whatever's the latest thing. (The GE BrightStik's appear to fall into that category due to their design, requiring less -- or no -- reflection.).
 

dufiwon

Well-Known Member
Nah its not ho just t5 4 bulb 2 foot fixture from htg. 96 watt with two 90 watt ufo led is what im running right now. The t5 heats up my cab and the leds are really old 1 watt 2nd gen ufo.
Your plant looks good.
 

littlejacob

Well-Known Member
Bonjour
I have a 3.5x3.5...but only 32 inches tall for vegg...I will use cxa 2540 x 9 @700mA.!
It will allow me to put the plant at 6in from my cob!
I will not flower in it but if you do supercropping and lst plus you add a screen it will be a nice scrog!
And 150w will be.great for your space!
Or 3 cxb3590 @1050mA too!
CU
 

az2000

Well-Known Member
The t5 heats up my cab and the leds are really old 1 watt 2nd gen ufo.
I think the inexpensive epi-whatever LEDs you're considering will be as hot as that T5 (non-HO) for the same results. I would scratch those off your list if heat management is a priority.

Some people do SMD5630 strip LEDs in shorter/smaller spaces. The nice thing is that they don't consume much of your limited space. I don't think they require much distance because the light is diffuse and spread out. There have been some threads about those. If you're interested I can post links.

My only concern is that I haven't seen how they grow. There's been alot of talk about how they might grow, but those discussions never seem to conclude anything. If you're the adventurous type, you could be the one to the guinea pig for the benefit of others.(?).

I would do it but got into the lightbulbs. I really like them.
 

Resinhound

Well-Known Member
If you have height restrictions like that you need to research,you need a light you can run at 12in or less,led or cfls seem like a good option here.Look at umol readings at 12in,you dont really want to exceed 1300 umols as thats pretty much the exposure limit for cannabis (cannabis show decresed growth rates above 1500 umol)if the company cant provide that information,its better to look elsewhere imho.
 

dufiwon

Well-Known Member
I want to build a cob light. My space is 36"w X 17"d X 42"t. How many cobs should i use? Which cobs would be best for an autoflower chamber??
 

littlejacob

Well-Known Member
Bonjour
Why autoflo????
Is fem seed too strong for you?
For me it is a waste of time...I have some...all freebies...I tried some outdoor to have weed earlier...small plants...fluffy bud...or if it have nice buds...no taste...maybe the new gen is better but indoor I prefer fem seeds!
CU
 
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