medicinehuman
Well-Known Member
For the price, that's a good deal. I wish I needed some.
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Not sure where you can get 2400w of Chinese epi-unknown fixtures for $415. Four MarsII 1200 panels (600w actual) will cost you $1750.
I've seen links to CMH fixtures that were comparable to that cost.
nomofatum
Well-Known Member
That is DIY buying parts from aliexpress/ebay + parts from local hardware.
What CMH fixtures do you recommend/use?
Ok. Getting back to imported Chinese epi-whatever fixtures (which had some people upset, starting this topic) it sounds like the "decision tree" is still as short and uncomplicated as I documented it last night. (<<link)
I look forward to seeing your decision tree for DIY, when to use Epistar chips for same, etc.
Mr. Nuggets
Member
Guess I'll chime in. Thinking about two LED fixtures, each quoted as 300w, so 100 x 3w, 4800lum. Would these two be a good fit for a 2' x 4' area? Thanks.
nomofatum
Well-Known Member
I assume you missed a 0 on the lumens? 48,000 lumens should work well in that space.
nomofatum
Well-Known Member
That sounds too good to be true though, 160lm/watt, what kind? link?
Mr. Nuggets
Member
No, 4800 is correct. If you're saying that 48000 would be required for a 2x4 space, then let's take the Apollo 6 for example. Which is 3600 lumens. Are you telling me that for a little 2x4 space, I would need 13 Apollo 6s?
With imported Chinese epi-whatever lights you'll need 40-50w/sq ft. Depends on the vertical height to some extent. If you're growing short plants in a 4-5' tent, 40w/sq ft might do. If you're growing taller plants in a 7' tent, 50 is better.
I have an Apollo 4 and it's intended for a 2x2 space. So, you'd need two of these. But, they're 130w actual draw, only 32.5w/sq ft. Supplementing is necessary (or, running 3 for 49w/sq ft). I imagine your 6-spot is similar. 32.5w actual per spot.
Also, IMO it's better to have more smaller fixtures. Better coverage, flexibility to position the lights to the canopy, and when (not if) a fixture fails it won't go totally dark.
How tall is your tent? How much will these lights cost? (Could be better options.).
Mr. Nuggets
Member
Tent hight will be 4.5' max, but can extend if needed. (custom tent) The lights are $100 each. How is your Apollo 4 running? Is it enough for 2x2?
nomofatum
Well-Known Member
I am running the epistars, looks like those have the red, blue, uv, and 6500 all together. The 6500 is likely the only thing registering on the lumen test. In my testing the red and blue didn't do well against the 3000k and 6500k epistars, the same fixtures that have white LEDs instead of red/blue/uv/white. If you look at them you should see a 300w fiture should show at least 27,000 lumens.
Mine does ok, but I ordered mine with a custom spectrum based upon Grow Northern's "rebel" spectrum. $150 delivered. The main point is that it requires more watts per sq. ft and generates considerable heat compared to more efficient LEDs available.
An Apollo 6 at $100 sounds like a good deal. But, with Chinese epi-unnown (chips) you usually get what you pay for. $100 won't be a lot to lose if it doesn't work out.
In a 4.5' tall tent you have to be aware of the distance required between canopy and light. Plus the space above the light for the fixture's fans to ventilate (pull air in). If you were intent on doing Chinese epi-unknown lights, I'd recommend fixtures with 3w chips mounted on white backboards instead of within reflectors like the Apollo. That will give you softer, more diffuse light. Should mean less distance required to the canopy, giving you 3-4" more growing height.
Without a link to the actual light you're considering it's hard to say. But, if it has 32.5w actual draw per spot, I'd recommend three Apollo4. Or two with supplemental light like this. (<<link)
nomofatum
Well-Known Member
How big a deal to extend? 4.5' sounds like a bitch to begin with, and it's quite limiting for both grow style and lighting.
Mr. Nuggets
Member
This is what I was originally thinking of.
http://www.dhgate.com/product/high-quality-100-3w-led-300w-led-grow-light/171687329.html#s1-3-1|827018358
I was thinking of doing 2 of these for a 2'x4' area.
http://www.dhgate.com/product/high-quality-100-3w-led-300w-led-grow-light/171687329.html#s1-3-1|827018358
I was thinking of doing 2 of these for a 2'x4' area.
Is there a reason you're considering LED instead of T5HO? If you haven't gathered yet, Chinese epi-whatever fixtures aren't well regarded. The one advantage they have is low entry cost. But, they're not known for longevity, warranty service, etc. Basically disposable and high energy consumption, high heat (compared to better LED).
If you're not concerned about the cost (for example, gonna sell the first 2 harvests and use the money to buy a better light), nor the heat (in a temperate climate), it's not a lot of money to put at risk. But, if it's a long-term investment, if you intend to grow in this space for a long time, T5HO might be better. It generates about the same amount of heat and better lumens / watt (92 lm/w).
If you were in a taller tent, a ceramic metal halide (CMH) is the common recommendation to anyone considering inexpensive Chinese epi-whatever lights. More light for the energy and heat. In a shorter tent, Chinese lights might make sense. If you wanted higher-efficiency LED there is Hans/Bonsai Hero. It's 3w mounted in reflectors, but they're wider angle reflectors. You could contact them to find out how close it can be. There's also the LED "lightbulbs" in that link I provided. Those are up in the 92-110 lumens/watt. More flexibility/coverage than a monolithic fixture. Easier to repair (bulb burns out, screw in a new one. Not dealing with soldered-on LEDs.).
Mr. Nuggets
Member
But how many T5s would I need for that area? I guess I could fit an 8 bulb fixture in the 2x4. Would this be enough? I've never worked with T5s before. I've used a 125w CFL for a mother plant in a 2x2 and it was fantastic! But never T5s. (I'm not set on LEDs, just figured like everybody else that you've found something in China that might work for cheap)
Those aren't Apollos. The white backboard is the style of light I'd recommend if you're going to put a chinese fixture in a 4.5' tall tent. If you're intent on doing that (instead of T5HO or LED lightbulbs as I linked to), the brand VIPAR on eBay is recommended by experienced growers here. (They recommend against Chinese epi-whatever lights for the reasons I've mentioned. But, as the best of the worst, VIPAR gets the nod.). TopLED/MarsHydro seems to have a fairly sizeable following (compared to what you linked to). They have a user support forum at 420mag. I think there's something to be said for that kind of public support (compared to dealing with someone privately through email). If anything goes wrong, you'll have some community involvement.
So, if I were going to buy a Chinese epi-whatever light, I'd do either of those instead of buying a relatively unknown brand.
When I ran T5HO I had a 4-tube fixture on top, and a 2-tube fixture in the rear angled down a bit like sidelight. 324w. I had CFLs on the corners, perhaps 20w each. I don't remember what they were. That's 400w or 50w/sq. ft. Rosenthal says in Grower's Guide that 40w/sq ft. is optimal, and 50 is the point of diminishing returns. I got 180g from half that tent, less than 1g/w but pretty good g/sq ft.
With higher quality LED you'd need 35-40w/sq ft for equivalent results. Less heat. Right now I run a Chinese epi-whatever UFO (85w) and 38w LED "lightbulb" sidelighting. 123w/sq ft. I pulled 155g last time. That's a good g/w energy use, but not as good g/sq ft.
So... that gives you what you're weighing. Do you want to be efficient or get the most output from your space? Does heat matter? Is it a long-term investment or is a disposable light ok?
At the prices of Chinese epi-whatever lights, as long as you know what you're getting into and why you chose that path, you can't be too disappointed.
Also, the reason I refer to them as epi-whatever is that they don't tell you the chips they use. Taiwanese Epistar may be a respected chip, but they're sublicensed across the mainland. You don't know what you're getting. Dies may be purchased by the fixture maker and encapsulated onsite to save money. There's not a lot of quality control or confidence (provenance) as there is with other brands. For example, Area 51 publishes the actual part number they use. You can literally make your own light if you want to. (The LED "lightbulbs" are a known chip.). But, I don't think the RW-75 would be a good choice for your 4.5 space. 5w reflectors. It will chew up some vertical space for the distance to canopy. (I have one.).
To illustrate how you can do better than CFL, they are 60-70 lumens per watt. T5HO is 92. Cree LED "lightbulbs" from Home Depot are 92 with the diffusion globe, over 100 with the globe removed. Lightbulbs from AliExpress using SMD5730 chips in clear globes are 105-110. DIYers here are getting 120-140 lm/w with COBs.
So, T5HO isn't bad. Whatever you do, in a small space like that it's easy to manage distributed lighting. You'll get better results if you supply some of those lumens (watts) from the sides.
In fact, if I were to do it again, I'd three 2-bulb T5HO fixtures instead of one 4-bulb and 1 2-bulb. With three, the two outer ones can be canted at a 45-degree angle. Better coverage IMO. (SunBlaze has 2-bulb fixtures for about $80.).
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