Thank you for your response mistascott. Do you happen to have a link to information about the lumens required for most plants. Your answer was definitely to the point but I know there is a bit of technical information involved that if I learn it I may better prepare myself for the purchases involved. I was actually looking at a 4' 4 bulb fixture and I'm glad you said that 6 would provide the lumens on par with an HID so I wouldn't have wasted my money.

There is no magic number of lumens required to grow a plant. The lumen density is sufficient with T5HO that you can grow anything you can fit directly underneath it, keeping the light fairly close to the plants. I would estimate that a 6 light T5HO setup would nicely cover roughly 12-16 square feet of grow space with plenty of light. A 400W metal halide typically covers a 4'X4' space so you'd expect the same from 6 T5HO bulbs. I'd also use sunlight to help if you can.

Okay, I was looking at fixtures and I've found one that I am wondering your input on it. It's a Quantam Bad Boy? It would be the 4' 8 bulb configuration. They sell it locally here so would that be a good one to get? They also carry Ultragrow setups as well. Ultragrow is cheaper but I'm curious on which you feel might be best?

Quantum: http://www.hmoonhydro.com/product_info.php?cPath=25_43&products_id=222

Ultragrow: http://www.hmoonhydro.com/product_info.php?cPath=25_43&products_id=223

Thanks for your input. I've been searching for product recommendations but haven't really found any.

I've used T5's a lot for full term. It is best to use all blue(6500k) or mostly blue for veg and then switch out half the blue bulbs for red ones to flower (3000k). Or you can just do half and half for all purpose also. The T5's don't have the penetration like the HIDs do so try and keep the plants under 2 1/2 feet for best best results, but I have grown taller than that with good results. A 2'fixture with 2 to 4 bulbs is good for seedlings and cuttings. They really only cover what fits directly underneath so a 4' 4 lamp model is good for lettuce, herbs, etc. A 4' 8 lamp model is close to a 400w HID in output and can do larger plants. I didn't have good luck with LEDs. I used a 90w UFO and was a waste of money.

The red/blue/Kelvin color temp thing is an underinformed aspect of indoor gardening in my book. You really need to look at the wavelength profile (often on the bulb box but not always) to see where the peaks are. Photosynthesis and flower/fruit production benefit when peaks are at specific wavelengths (see link below), but you can get plants to flower with pretty much any T5HO fluorescent lamp. I have two "6400K" AgroBrite T5HO bulbs ($8 each) with some supplemental winter sunlight on my hibiscus and it puts out between 2-9 blooms a day indoors. All fluorescent bulbs cover the light spectrum necessary for leaf and flower growth. The 6400K merely refers to the overall appearance of the light to the human eye. Higher numbers = bluer looking light, lower numbers = redder looking light, but that tells you nothing about the overall wavelength profile of the bulb. Sure, you might want to get bulbs that emphasize different areas of the wavelength spectrum (the Kelvin number does not tell you this fully though blue looking light probably has more peaks in the blue wave range), but this is far from essential to get plants to grow leaves and flower. The "penetration" idea is another myth: HID lamps provide much more concentrated light, so it appears brighter and hence appears to "penetrate" more. Due to that concentrated intensity, they are also much hotter than florescent light, which is why it is best to keep those farther from the plant. OK, enough with my soapbox. In the end, you will find out what works best for you.

I don't really have any advice on those two products you link to as I have never used or seen them. However, it would be best to get the bulbs in person because of their fragility in shipment.

Here is a link that might be useful: Some more info on photosynthesis wavelengths...

Thanks for the responses guys. I'm going to the Hydroponic supply store today to pick up the fixture. I'm going to look at the bulb boxes and see what the wavelengths are if they are even on there. Push to shove, I'll ask the store attendees. Hopefully they are privy to their products. After it's set up and stuff, I'll post pictures! :D

Best of luck to you. This is fun stuff -- much more of a science than outdoor growing because you have the ability to control everything from humidity to light to temperature. Enjoy!

I purchased 3 4' 8 bulb T5HO 54W fixtures this year (Hydofarm) with 6400k bulbs. They seem to be pretty good, plants are growing way faster then expected. They are rated at 40,000 lumens per fixture. I meassured the LUX at plant level and they range from 26,000 in the middle to 17,000 on the ends. This type of intensity should be good to grow mature plants? I have also purchased some 3000k bulbs for when we want to get some on the flowers going. Good lights seem to make a difference.

DBA,

That sounds like plenty. You don't need 3000K bulbs for flowers (any fluorescent bulb will provide the right red wavelengths to produce them), but it probably won't hurt to throw them in to emphasize the red wavelengths just a little more.

How close are the lights to the plants? If they are growing well, I would leave everything as is. Don't mess with what works!

I had them 3-4" away but the heat was too much and the drying a problem, now about 10" from top of pots or flats. Like I said , I'm getting > 20,000 lux even at the distance with these. Probably could have gotten away with 4 bulb units but real happy with these except things are growing faster then anticipated.

I've had success with using T5 HO lights in my basement growing plumeria from seed. I put the plants outside during the few warm months that we have in northern Utah. I've had one and two year old seedlings bloom, which is quite unusual for plumeria. Usually it takes much longer for plumeria seedlings to bloom. So I'd say yes!

Good LED's work well also. Those cheap UFO's are junk however. You need to do your research, as there is good and bad in the market for LED lights. Given the right ones, they can do very well, and the technology is in constant improvement. Many people with bad results are using cheaper/older systems. They have come a long way.

I personally am having good luck using a combination of T5HO's and a 120W LED. I've used it for two years now with good results. Things have improved a lot even in the last two years.

I plan on upgrading to a 200-300W LED unit for mature plants, and keeping the T5HO's for seedlings. Eliminating the T5HO's from my LED room will make up for the additional power of the larger unit.

Experience tells me that the only lights for serious growing are HIDs. They deliver much more lumens per watt than anything else, drawback is that spreading that light properly is a bit tricky.

Oh btw for those who think HIDs are out of price, there are countless failed cannabis growers who just wanna get rid of their stuff on kijiji or craigslist...got myself a kit of 20 1000w hps ballasts for 1000$ recently...

MisterK, your lumens per watt statement isn't true: T5HO lamps deliver about 92 lumens per watt. HID lamps (metal halide) average around 90. The lamps distribute the light differently, though (narrow long band vs. point source). You do get more bang for your buck with HID though (less $ per lumen).

I don't know much about LED other than they are uber-expensive right now.

Mistascott: no offense, but ill stick to my guns...a 1000w hps light produces 145000 lumens, thats 145 lumens per watt. 600 watters do even better, at 158 lumens per watt.

What you are stating is probably for the least efficient of metal halides out there...

T5s maximum efficiency is at 92 lumens per watt...hid minimum efficiency is at around the same level. Real life experience shows us that hids destroy t5s in performance.

Now i agree with you on narrow band vs point source, but if you go the circular vertical grow route, youll be able to maximize effectiveness of that point source lighting

I was referencing a 400W metal halide, which is typical of what an average small-scale home grower uses. That typically produces 36,000 lumens. The highest efficiency metal halide I have seen produced 125 lumens per watt. My point is that metal halide isn't head and shoulders more efficient than T5HO. HPS is a different animal altogether and I agree it is much more efficient than T5HO at 140 lumens/watt. However, HPS's limited wavelength profile (red/orange) tends to make it less favorable than metal halide.

@mistascott: i think weve found the middle ground :)

I agree with you that metal halide is most widely used, however hps is what you want for flowering...

My beef with the t5s is the cost of acquisition vs performance delivered...they are good for a hobby grower who doesnt really consider economics, however in my case, i am starting a fairly large indoor grow, and thus going the vertical circular route with mh seems better...but t5s allow easier tiered systems, for example shelves that allow vertical use of space...

I distrust the new lighting techs out there...most of them are not ripe for market in my opinion, led being the biggest misconception of them...

At your scale of growing, certainly HID is the way to go. For small-sale seed starting though, I would highly recommend T5HO as an energy efficient and cost effective option. You can get a decent fixture and bulbs for only 1-2 hundred $$.

Do you use HPS only? If so, do you get leggy plants or do you get dense leafy growth too?

*sale= scale

Also, I only ask about HPS because I have always been told they require additional light to get blue wavelengths.