Newbie here saying hello

[GpsFrontier]

Hello shillamus,
It depends on what your growing with it and how you have things set up. cfl's are the same thing as T5 florescent lights, except their more compact. hence the term CFL (compact florescent light). CFL's have the ballast in the base of the bulb, straight tube florescent lights have the ballast in the light fixture.

Weather their compact or straight tube, all florescent lights have the same issue. The usable light range is very short. The luman drop off rate goes way up beyond 2 feet from the bulb. In other words at 1 foot from the bulb your getting about 85% of the usable lumins/par to the plant foliage, at 2 feet your getting more like 60%, at 3 feet from the bulb your only getting about 25% of the lumans/par reaching the plant, at 4 your getting basically no usable light. Same goes for led lighting.

While a 200 watt CFL will concentrate more lumans/par in one area, the coverage area is smaller. As an example four, 4 foot T5 bulbs equal 216 watts and will cover 8 sq feet of area. While a 200 watt CFL will only really cover about 4 sq feet. So the wattage is about the same but the coverage area is cut in half. You don't need 200 watts per 4 sq feet to grow lettuce. It would grow faster because of the higher light intensity. but not really worth all the extra electricity. You would be better off with the larger coverage area and growing more plants.

With that said fruiting plants take about twice as much light intensity (par/lumans) to support the fruit. While it is possible to grow fruiting plants with florescent lighting, it's not cost effective. Watt per watt your much better off using HID lighting to grow fruiting plants, especially large ones like tomatoes.

As for spectrum of florescent lighting, higher wattage doesn't mean better spectrum. It means higher light intensity (output). Unless the manufacture is selling their lights in the hydroponics industry they don't usually provide a wavelength (spectrum) chart for comparison. It's not that florescent bulbs sold in hydroponics shops are necessarily better than standard bulbs and that's why they provide the charts. Manufactures selling their florescent bulbs for household and shop lighting don't need a wavelength chart because people buying them for that reason aren't comparing wavelengths. They compere the color of the disable light by the K value. They typically range from 2400K to 6500K. The lower the K value the more of the red spectrum the light puts out, the higher the K value the more of the blue spectrum there is.

[newhydro16]

Thanks again GPS told you Id be a pain in the butt

[GpsFrontier]

Hello newhydro16,
While helping people is time consuming, I don't mind trying to help people who want/need the help. The way I look at it is if I help you be successful you can help someone else be successful later. That's what makes the world go around.

[Davephan]

How about using 150 watt HPS lights instead of 4 tube, 4 foot fluorescent lights? I use a Sun Systems 315 watt LEC for the grow area, and I am thinking about adding several Sun Systems 150 watt HPS lights. Those 150 watt HPS lights are less than $60 each, cheaper than a 4 foot, 4 tube fluorescent light. I have 4' x 2' metal shelves, and I was thinking of installing one 150 watt HPS above each shelve.

[GpsFrontier]

Hello Davephan,
It all depends on your spacing, location, and how much your growing. HID lighting will give off more heat so they need to be farther away from the plants which isn't a problem since the luman drop off rate is much lower with HID. However if your growing in stacked rows like shelves the extra height needed may be an issue. Also With a 4 foot florescent light you get even lighting along the the 4 foot length. Where if you used one Hid bulb in the middle, the plants in the middle will get a much higher light intensity, and the ones around the edges would get lower light intensity, so the growth rate wont be even. You also may have an issue with light shading. That is the plants closest to the light blocking/and shading light from the plants farther away. With multiple bulbs you can reduce light shading problems, as well as get even lighting over the whole coverage area.

But if your looking for more coverage area, HID lighting certainly is the best option. It all depends on how much coverage area you need. That all comes down to planning. Deciding on how many plants you need to grow, how much coverage area you need, where you will be growing, how you will be growing. Even controlling temperatures all come into play.

But ultimately you could easily get more coverage area out of using multiple low wattage HID lights than florescent lighting. As an example 4 T5 lights (216 watts) would easily cover a 2x4 foot space (8 sq feet), but 2, 100 watt HID lights spaced evenly could cover a 6 x 3 foot space and could more than double that coverage area (18 sq feet) using about the same wattage.

P.S.
Do the $60 lights your talking about come with the light fixture and ballast? I'm aware of a 100 watt HID light that comes with the fixture and ballets, but runs about $114. Mini Sunburst MH w/Lamp, 100W