HelpfulGardener.com

Seeds, check
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Containers, check
Waterbed heater with thermostat, check
Lights.... Lights.... Ummm

So this year I decided to start as much in doors as I can. With substantial help from this forum, I have accumulated the needed items to be successful with this new venture, with one exception that I am still exploring. Living in West Michigan, we are lucky to have a few sunny days in the summer. In the winter forget about it. So I am looking at lights, but have a question regarding wattage. I plan to go with 6,500 K lights since it will only be vegetables. I am also looking at a single 4 bulb system that will be 4 feet long. I found more T-12 than T-8 bulbs and not nearly as many T-5 bulbs, but I am still looking. I have not purchased any of the lighting equipment yet because I have not determined exactly what I want.

I have found several different T size lights, but within each size category, I have found several wattage options. I am extremely cheep and need for this to be as cost effective as possible. So I don't want to spend extra money in electric bills if the additional wattage is not needed. I am a big fan of long term savings over short term cost. (Every light in the house is a CFL or LED), so even if it is a bit more now but will become cost effective within the year, that will be good enough for me.

So with all that, what Wattage do you use?

2-bulb, 48" shop light with 32W T8 bulbs at 6500K. Perfect.

Picture of the setup and actual cost breakdown on my blog. Cannot seem to get the pic to post to this post for some reason.

Hope that helps!!

M.,

Are you talking about seedlings or growing plants to maturity? And what type of veggies? Tomatoes and peppers, for example, need a lot more light than lettuce or chard.

Mike

wordwiz wrote:M.,

Are you talking about seedlings or growing plants to maturity? And what type of veggies? Tomatoes and peppers, for example, need a lot more light than lettuce or chard. --- to grow to maturity (RBG addition)

Mike

But if you are just talking about growing seedlings to transplant size to move outdoors later, any standard fluorescent will do.

I have used T-5's and T-8's and haven't noticed a whole lot of difference.

It will be peppers, tomatoes, cucumbers, eggplant, greens, and anything else I can get a jumpstart on. I may even try corn using small containers made out of paper towel rolls sections.

All of them will be transplanted outdoors into a cold frame once the weather starts to break. Living in W. Michigan, we don't have a very long season and I am hoping for second harvest with as much as possible, so I want to get as much going as possible early.

I plan on putting the cold frame on the beds in mid to late Feb to start warming them up, and then planting the root veggies (carrots, beats, onions) sometime at the mid March. Then hope to have everything in by the second week of April.

M.,

In that case, as RBG typed, any fluros will work. I like the 5000-6500 Kelvin bulbs for seedlings - they don't need the red spectrum.

FWIW & IMO, if you have limited space, it's not worth donating to corn. Even at supermarket prices, I can buy 10-12 ears for $3 in harvest season. Yeah, I can grow it for less but if I look at the return per square foot, corn has a low yield.

Mike

I use the four foot, twin bulb shop light fixtures with two 32 watt T-8 bulbs with the ordinary cheapo cool white bulbs (which is in the blue spectrum for veggietative growth) for covering an area of 11" x 48", or two flats with 10" or so left over at the end for a few more 4" pots.

So thats 64 watts plus the cost of running the ballast for roughly 4 square feet of growing area. In 30 days, running 10 hours a day, my tallest seedlings are reaching the 5" mark with widths of 10" in 4" pots and need a bit more light so I add another twin bulb fixture and space the plants out a bit. If temps are warm enough in the coldframe by day then I can bypass the doulble light fixture and shuffle the plants outside for the day.

I know the T-5's are higher output and believe they would be better for growing taller plants but they are expensive to purchase and suck up more juice. I'm sure a four bulb T-5 system would grow better plants faster but I'm very happy with my starter plants and would not consider them to be leggy by any stretch of the imagination.

I've also grown award winning African violets (which are considered low light plants) with a combination of one cool white bulb (blue spectrum) and one warm white (red spectrum) bulb which triggers the flowering. So the shop light system is cheap but effective.

Hope that helps.

From my blog regarding GROWLIGHT EXPENSES:

Ok, so how much does it cost to purchase and operate artificial lighting?

Lighting expenses continue to be a concern for my indoor growing endeavor because I want to keep this cost neutral or preferably net positive if at all possible. After all, this is "Frugal Hydroponics" right?

The lights I use are simple 2-bulb, 32W, T8, 48" shop lights with on/off pull chains. "T8" fluorescent bulbs are much more efficient than the standard T12 40W bulbs. "T5" systems are more expensive for the initial purchase, but are more efficient than the T8s. I may switch to T5 in the future, but for now I am happy with the results and efficiency of the T8 system.

I bought 3 of these shop lights for less than $9 each and fashioned them together to operate as one 48", 6 bulb fixture of which all are plugged into the same light timer. In effect, I have 6 32W bulbs covering a 48" x 24" growing area. This easily accommodates several standard starter trays or least 3 of the hydro systems. I recommend watching your local big box stores for sales and manufacturers rebates. The lights I bought normally retailed at over $20 each, so wait for the sale.

Since vegetative growth is achieved in the "blue" spectrum, I use 6500k bulbs. A 2-pack of Sylvania T8 6500k bulbs is around $3.50. Since I am growing lettuce, herbs, and my spring starters, the blue spectrum is all I need. If I were to grow plants requiring a flowering stage (peppers, cucumber, tomatoes, decorative flowers etc.), I would need red spectrum bulbs and additional shop light fixtures. At this point, I believe that is cost prohibitive for me as I will grow those type plants outdoors.

Calculating Energy Consumption: 32W bulb x 6 bulbs = 192 watts. 14 hours of use per day x 30 days = 420 running hours. 420 running hours x 192 watts = 80640 monthly watts used. 80640 / 1000 = 80.64 Kilowatts used. My energy company charges $.0783 per kilowatt, so my total monthly expense to run these lights is $6.31.

Expense re-cap: Total cost of shop lights: $27. Total cost of bulbs (replace yearly): $10.50 or $.875 per month. Total energy usage per month: $6-$7.

I feel this is economically feasible for the production I am wanting to achieve. I recommend researching "High Intensity Discharge" systems for anyone wishing to produce flowering plants or increasing production by several magnitude. These systems do require many additional considerations, so research diligently.

Sorry, but my comment on the T-5's using more electricity was based on using the 54 watt bulbs. Not by much but look at the output numbers! Should have been clearer.

Also Halfway, I did'nt realize the T-8, 6500's were that inexpensive. I'm in need of some replacement bulbs and I'll see if I can pick them up. Wonder how noticeable the plant growth will be between them and the 4100's that are getting very tired.

Anyway, I did some comparisons...

(Two) 32 watt T-8's = 5,600 lumens, or 1,400 lum per sq. ft.

(Two) 28 watt T-5's = 5,800 lumens, or 1,450 lum per sq. ft.

(Two) 54 watt T-5's = 8,900 lumens, or 2,225 lum per sq. ft.

So it appears to not be a huge savings in electricity unless it comes down to ballast which I have no idea about.

It is recommended to have 1,000-3,000 lumens per square ft of growing area.

I bought a case of 12 48" Sylvania T8 6500k for $33 and some change. I've seen them on sale for $2 each, but I needed them so I paid the full price this time. Try this and watch the box stores for specials. https://www.nextag.com/48-t8-6500k/stores-html

T5 are the most efficient when it comes to lumens per watt, though the fixture and the bulbs are more expensive in direct comparison. Same with T8 being more efficient than T12...improved technology.

If I decide to attempt fruiting plants, I am leaning towards a 4 bulb T5 High Output system. It runs about $150 and the bulbs are $4-5 each, but it is strong enough to effectively penetrate the canopy of taller plants and provides a long-throw "red" spectrum" with the proper bulbs.

This would be cheap (to me) versus a 400W HPS and the associated electrical bills, cooling requirements, humidity etc.

Well, I'm still running a few older light fixtures (built like tanks) with ballasts for the old T-12, 40 watt bulbs so I broke down and picked up replacement bulbs in the 6500K with use of my gift card. Curious to see if they outperform the very old T-12, 34 watters that were wrongfully placed in in the fixture.

I had two options, the T-12, 40 watt 6500k at 3050 lumens, or the T-12, 40 watt 4100k at 2800 lumens. So thats a small gain of 125 lumens per sq ft, not a big deal.

Some of these old fixtures even have two threaded sockets for screwing in incandesent bulbs to promote flowering! LOL Oringinally made by Tube Craft Inc, in Clevland Ohio. No wonder they still kicking!

Hopefully all will be well.