T-5 measurements at 3-4 feet away?
 

Could someone measure the intensity of their T-5 lights at 0 feet and 2, 3, and 4 feet down? I know it's a big request, but I am considering all T-5s instead of a metal halide/T-5 setup in a 4 foot tall wardian case setup, and I am just worried if I have little plants 4 feet down that it's going to be too little light. Like I have 1500 fc from my Compact florescent 36watts, but at 18" away I get only like 400 fc...

Thanks, Bill

Look at my two terrariums. Hight of the two are 120 cm about 4 feet high smaller one has 3 x 36 watts t5 and larger one 5 x 80 watts. So it depends on total watts and area that has to be lighted. And also what kind of reflectors you have. Still in play comes the spectrum of the lights. you need the red and blue to grow and flower your plants. Hope this helps you.

I have a 4 tube bank (48") and right at light I measure 2800FCs. A foot or so down It drops to about 600 FCs (to be expected) at 24" it drops to 150-200 FCs depending on where I measure it. Hope this helps.

That's kinda what I expected, I mean I knew it dropped of logarithmically, but I don't know how people achieve the high light levels that some plants need, while not over lighting them at the tops...

I guess I'm going to have to make moveable shelves or something like what you have going on with that hanging light. <grin> I know I was a bit critical of it, but that seems to get the light everywhere...

Another thought... aren't you referring to your new orchidarium? Why not reserve this tank for two types of plants: those that grow at intermediate light (1500-2000 FCs) and those that tolerate or seek lower lights levels like 500 FCs? Then if you need higher lighting, try a larger fixture. I'm debating a 8 tube 48" fixture for a new setup.

Oh, sorry, missed your response... I'm only making the larger tank to enable me to grow larger vandas! So... yeah, an 8 tube 48" setup could possibly work... but it all comes down to price and lumen output... If I can do the T-5s myself, it would be nice to have even light output, right now I'm considering 2 x 150w MH + 1 x 150 w HPS... but a 8 bank T-5 setup is in the running... I'm trying to DIY most of it to save $, and it's easier right now to pick up a 150w MH/HPS ballast for 30$, bulb for 40$, and reflector for 40$ than piece together a T-5 system which has so many more parts that it's hard to find a discount on them. I'm trying to stay within the 250-300$ range for lighting.

Did you see a 8 tube 48" fixture of T-5s that looked promising? I forget that link of the one you reccomended earlier...

Found a decent price, ~270$ shipped with bulbs probably... Just wondering about the bulbs that come with them and how good they are, mixed 6500k and 3000k

Sun Blaze 432W 65K/3K 40000 Lumens 4FT T5 Fluorescent Grow Light - Plantlighting Hydroponics

I was using a sunblaze 44 (4 tube) when I gave you the other light measurements. But I have had some trouble with that fixture (not all tubes were same brightness, and overall brightness not what I originally hoped). I contacted company and they offered to replace ballast for free. It has a 5-year warrantee. But I needed a replacement fixture while it was gone. I went with this one: New Wave T5 Light, New Wave Florescent Grow Light, New Wave Fluorescent Growing Light, New Wave High Output T5 Lighting, Low Profile New Wave Grow Lights They are more expensive but come with bulbs. I got mine with 4 - 6500 tubes and bought a single 3000 tube. I have a 3 to 1 mix for approx 5000K. They sent GE brand which are really good lights. Here's my new light readings:

at lights: 2900
10": 1600
14": 1400
24": 700

These represent (except for at lights) the staging of my plants. If you compare these to the earlier posting you can see how far out of whack that fixture/tube combo was. I still don't know if it was the tubes (chinese knockoffs) or the ballast. But I like this light. It is hung about 2" off top of tank for ventilation/heat control and I am running three small A.C. fans to blow away heat.

Bulbs are $13.99 with the fixture (first set is included iin price) and $15.99 ordered alone. This fixture can be hung horizontally or vertically with included hardware. This company is extremely friendly to deal with. Check the above figures, you may not need the 8 tube fixture. Oh, and this fixture uses the 95% reflectance german aluminum and is 2" wider than the Sunblaze.

Check out 4hydroponics.com for T5 units. I buy my 4 bulb 48" New Wave there for $215.95 with free shipping for orders over 250.00

Thanks Grandma M, that site does have pretty good prices. Did you get the correct fittings this weekend? :)

That's a huge improvement Ross, I'm still torn as to the T-5 vs. MH... cost wise. I've been reading up on T-5 vs. MH. I am a MH DIY ragabond, so it's hard for me to be pulled away from all of the tinkering with MH for a Plug and play T-5 system. I'm wondering if I could expect double of the light you have from a an 8 bulb system, since at 2 feet you're at 700 fc, I'd be happy with 1400 fc.

I never posted what my measurements with a decent reflector and 100w MH bulb did... it's covered in 2 tubes (it passes through 2 tubes to get out), so it's actually not a great setup, but it's plenty of light for my small 18" wide x 18" deep x ~24" tall setup.

at the bulb it is 12,500 fc
6" down it is 2,500 fc
12" down it's 850 fc
18" down it's 500 fc

My vanda/asc princess mikasa is about 8" down, which has about 1400 fc and is doing great... so, although the normal recommendation is for more light for them, but I think it's fine if I get that amount to all of them.

I found a good thread on the coral reef forums, apparently there is a good article coming out by Dr. Sanjay Joshi comparing the two in a head to head battle... not out yet if you check the last page (20) but I'll be sure to post when it's out.

Whenever I get into looking at new lighting systems, the price just keeps getting ratcheted up and up and up!!! gah... just means It gets delayed as I save more $$$.

Reef Central Online Community - T5s vs. MH... What would be the ultimate faceoff?


The big point in that thread is that optics makes a big difference in the systems, the tek systems being the best bargain, but not necessarily the best optics... then I think the new wave is a step up... and it ends up being a never ending spiralling cost to get the best... I think I may just toss in the 150 and 100watt metal halides I already have and see how they do... do a "scaled" upgrade, or maybe just sell those systems... Probably by the time I am ready to get the lights Sanjay's article will be out...

Okay sorry to pull this thread back up! :) So I'm just curious - how is it that the MH drops from 12,500fc at the bulb to 850fc at 1 ft away, whereas the T5s only drop from 2900fc to 1500fc at 1ft away? Is it a result of the MH being a point source versus the T5s where the length of the tube emitting light 'adds' to itself?

The reason I ask is that I'm setting up 2 encosures - one that's relatively taller which I hope to use the MH bulbs I have (and that oclearis totally helped me out on), and one that's shallower which I hope to get the T5s Ross recommended.

I'm realizing now that I'm doing more indepth research what a huge bag of worms this entire lighting thing is, and all the controversy there is surrounding this topic. Being poor that I am, I don't have the luxury to try different things so I want to be sure.

I was reading on another forum that for price purposes, people even go with T8 lights and overdrive them...besides the fact that wiring stuff scares me, I'm not really too keen on this since I feel like the lumens/watt go down, despite the fact that you're getting brighter light.

Well, the T-5 do have a more even output of light for low height shelves. I believe they should scientifically drop off at the same rate, but since the fluorescent tubes are over a much wider area, it's easier to get close to the maximum possible drop off. Where as with Metal halides only at the very center will you get that max.

T-5 are a high output T-8 basically. By default the T-5 ARE a high output. Where as the default T-8 is a normal output. That's where the greatest increase in lighting comes from. Not that T-5s aren't a decent increase in efficiency, but the nature of the game is lopsided in their favor.

If you're on a budget, you can pick up a 4-8 tube T-8 setup for under 50$ at any home depot/lowes, and will be sufficient for phals/paphs etc... anyways. If you really want to kick the light up a notch, T-5s are the way to go, but just because it's a newer technology doesn't mean it makes all the past obsolete.

I agree with the above. There are lots of Orchidboard members successfully growing and blooming various orchids under t8 setups.

Makes sense -thanks oclearis!

I found good T5 bulbs being sold at a reasonable price at a local hydro shop, so I think I'm going to go with the new-wave fixture you recommended, Ross. It fits the size of my tank better than anything else.