Differences between HPS/MH lights and regular flourscent lights for growing indoors?

Question

so my research results tell me that many people out there dont go after professional lighting systems, instead they use those compact flourscent bulbs or any other shape for growing plants indoors... NOW THIS IS FOR THE EXPERIENCED: Overall how much of difference do these 2 types of light make on the final product... Does it "really" matter or i'll be fine using the flourscent lights... I've got everything else perfectly down for a water culture system including the nutrients!

Answer 1

Yes, it really matters. Plain flourescent bar lights do not contain enough light spectrum for plants to grow to their potential. Imagine that each wave of the light spectrum is a vitamin that the plant needs.

Now the HPS and MH bulbs containg the largest spectrum of light and that is what makes them perfect.

The MH light will mimic the spectrum of the summer sun which in turn will cause the plant to stay in it's grow cycle.

When you wish to "flower" your plant, you switch to the HPS bulb, which simulates the autumn or "red" sun. After cutting the light cycle back to 12 on 12 off. The plant will be forced into it's flowering cycle.

I would go to a hydroponics store and pick up a HPS bulb and a MH combo bulb with a balast and you are in business-

Answer 2

Fluorescent tubes are the most economical and convenient in limited areas. In the fluorescent tube, special phosphors become excited as electricity is supplied to them and give off energy in certain wavelengths. It is possible to design these tubes to emit primarily red, green, yellow or the "color" of your choice. Not all are equally efficient, but this would appear to have a practical application, since plants do not use all wavelengths with equal efficiency.

To achieve better efficiency in the response of plants to fluorescent light, special tubes have been designed which emit proportionately more blue and red wavelengths of light. In doing so, the green-yellow-orange fraction has been reduced. The loss in this portion of the spectrum, even though it is slightly efficient has not been compensated by enough increase in the blue-red portion of the spectrum to result in increased plant growth.

Critical experiments show that maximum growth of most plants under cool white fluorescent lights will be equivalent to or better than that obtained under the blue-red phosphors.

Metal halide lights were created to provide a spectrum as close as possible to that of the natural sunlight. This coupled with their intensity and energy efficiency, makes them ideal for indoor gardening...

Fluorescent ballasts and bulbs are very inexpensive and much cooler and more efficient than incandescent bulbs. In marijuana cultivation, fluorescent lighting is useful for growing seedlings and rooting clones, because the light produced is very gentle (unlike HIDs, explained next), and won't burn young and/or sensitive plants. Fluorescents are available in 'warm' and 'cool' spectrums, with 'warm' providing more light in the red spectrum and 'cool' providing more light in the blue spectrum. Cultivators generally use 'cool' bulbs in order to encourage short internodes.

Metal halide (MH)

Metal halide bulbs produce light that is strongest in the blue spectrum, technically about 4000 Kelvin, or around 460 nanometers. Metal halide bulbs also come in various coated varieties intended to increase the red spectrum, but these are all inferior to a high pressure sodium in the red spectrum.

Metal halide bulbs produce about 65-115 lumens per watt and last up to 12,000 hours. They are available in vertical (BU or BD), horizontal (HOR), and universal (U), which may be burned either vertically or horizontally.

Metal halide is an excellent bulb for vegetative phase of growth, as it encourages short internodes (distance between sets of leaves), and inhibits cell elongation, creating a shorter, stockier plant. Growers with a single ballast often purchase a high pressure sodium ballast, and use a metal halide conversion bulb (a metal halide bulb designed for a high pressure sodium ballast) during vegetative phase.

Unlike high pressure sodium bulbs, metal halide bulbs also produce ultraviolet radiation, which may play a role in increasing the amount of THC produced by the plant.

High pressure sodium (HPS)

High pressure sodium bulbs produce light strongest in the red spectrum, technically about 2,200 Kelvin, or around 660 nanometers.

High pressure sodium bulbs produce less heat and more light than metal halide bulbs, producing 97-150 lumens per watt, and they last longer as well, up to 24,000 hours.

High pressure sodium bulbs are excellent bulbs for the flowering phase, and the choice of most growers who have only one bulb. High pressure sodium bulbs are an excellent choice for the reproductive phase of growth, as they trigger a greater flowering response in the plant, and simulate a more autumn-like light spectrum. A high pressure sodium conversion bulb, a high pressure sodium bulb designed to be burned in a metal halide ballast, can be used during the reproductive phase if a grower has a metal halide ballast.

If high pressure sodium is used for vegetative phase, plants will usually grow slightly more quickly, but will also have longer internodes, and may be taller.

I would prefer heigh-pressure sodium lamps .....humidity should be 60%-55%  temperature should  20 -22 degreecelcius.....good luck.