HID lighting

Hey guys,

I have been thinking of getting an HID light kit to illuminate a 4' x 8' area in my room. the height of the ceiling is approx. 7.5'. I grow mostly complexes and parvis. What do u think I should get? MH/HPS? wattage? Distance from plants? Is it necessary to get a light mover the evenly distribute the light over the 8' length? Hope to hear from you HID growers! Thanks in advance!

HPS will give you more light intensity(but is harder on the eyes).u have the same ceiling height as me which makes having a 1000 watt tricky...but if your plants are on the floor its a perfect scenario, as you wont need to move the light. a 400 watt light only covers a 4 x 4 area effectively...i would buy two if you go that route(if you have the dough because generally the systems cost the same) .digital ballasts are nice but the nondigital ballasts will last longer (and they are cheaper). you could d a 400 watt and a mover but movers are just as expensive as a system. I grow in a 4x4/7x7/4x4 area with a 1000 watt halide in the center and two 400's on either side (one of them is HPS)...the plants love it. i also grow parvis... they do well under the 400 watt about four feet away..i dont know abut complexes..i grow my multi forals about 6 feet under the 1000 watt and they love it

also 12/12 is perfect for the plants...u will have to fertilize more also...i fertilize heavier every other watering. The lights also put out a lot of heat..so you will have to consider humidity requirements also...but overall its the best thing you can do for your plants....mine love it

I think you could do either one honestly. Yo just have to adjust distance. I'd bet you'd get better coverage with the 400 w on a track compared to a stationary 1000 w with a long distance to the far ends of the room. If you do 1000 watt and make sure you cool the room or vent out the lamp & ballast heat! The 1000 w probably isn't necessary unless you have some light hungry plants, and IMO it'll just mean you're watering three times more frequently. In this case, semi-hydro works great!!!

You want both red and blue light essentially. HPS gives strong red/yellow, MH gives blue. Pot growers use each in sequence to get growth (blue) then flowering (red). In a mixed collection of orchids or whatever with random bloom seasons depending on what's growing, you want both all the time, so you'll need either 1) both HPS and MH in one fixture or 2) two fixtures, one HPS and one MH or 3) one bulb that gives all the wavelenghts you need.

3 is very doable if you shop for the right bulb! You can get HPS with extended blue AND MH with extened red now. Not sure what you can get in Canada, but before you buy, look at the output spectrum of the bulbs you're considering. You want a bulb with strong blue AND red output. When you find the bulb you like, get the ballast to match.

For MH, we've found SunMaster MH Neutral Deluxe bulbs to be awesome for orchids. The spectrum is very good for blue and red plus CRI (color rendering index) is excellent. Your eyes won't go batty in the room after a while. There's also a SunMaster 1000w MH Warm Deluxe, but we haven't used these.

Electronic ballasts are more expensive, but will run a little cooler. Some say more effecient, but a 1000 watt bulb requires 1000 watts regardless of the ballast that runs it.

I'd go with two 400 watt CMH lamps. This type of bulb uses HPS magnetic ballasts only (you can't use digital ballasts with these lamps), and the spectrum is full, balanced, and easy on the eyes. You'd have to purchase two 400 Watt magnetically ballasted HPS fixtures and two of the 400 Watt CMH bulbs. I've had good luck with this supplier when purchasing these bulbs. This is what I am currently using to grow my orchids. It's the best source of artificial lighting I've used to date. I've been growing orchids for 28 years and for at least 13 of those years I've been doing it under artificial light.

thanks for all the great info guys!

Now i'd like to know whats the difference between Digital ballasts and non-digital ones? Also I have seen both HPS and MH bulbs with enhanced spectrums available. which is better than the other? 400 w or 600 w sound good right now as the room is only 14' x 10' and with a 1000 w i think I'd have problems with heat.

How far do you guys put your parvis/complexes from a 400/600w bulb? Would the distance be the same even if a light mover's used?
What's the ideal size of reflector? Does it affect coverage?

Again thanks,
ardenn

Lanmark said:

I'd go with two 400 watt CMH lamps. This type of bulb uses HPS magnetic ballasts only (you can't use digital ballasts with these lamps), and the spectrum is full, balanced, and easy on the eyes. You'd have to purchase two 400 Watt magnetically ballasted HPS fixtures and two of the 400 Watt CMH bulbs. I've had good luck with this supplier when purchasing these bulbs. This is what I am currently using to grow my orchids. It's the best source of artificial lighting I've used to date. I've been growing orchids for 28 years and for at least 13 of those years I've been doing it under artificial light.

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Lanmark,

their Sun System 2 HPS MH Switchable 400 Watt looks promising. is thiswhat you have?

I wouldn't do a switchable ballast, that usually means you can only burn one bulb at a time.

Hey Ernie,
I wasn't thinking of using two bulbs at once. I just thought it would be nice to be able to switch from hps to mh if ever i want try different bulbs.

papheteer said:

Lanmark,

their Sun System 2 HPS MH Switchable 400 Watt looks promising. is thiswhat you have?

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Yes, one of my fixtures is a Sun System 2 HPS MH Switchable 400 Watt with magnetic ballast, but I didn't purchase it from them. I bought it in person from a local store. My other systems are nonswitchable but otherwise the same. Some of them were purchased from the retailer at that link. However, the nonswitchable style HPS magnetic 400 Watt Sun System 2 has been discontinued. There are switchable digitally ballasted all-in-one systems and switchable digital modular ballasts on the market which you must avoid if you plan to use CMH.

I don't grow the types of plants you grow so I can't advise much on heat or light intensity. I grow my orchids in my semi-finished basement where the natural ambient coolness mitigates any heat problems I might otherwise encounter from using HID lamps. You may only need one 400 watt or one 600 watt lamp for your grow space, especially if you use a light mover system. 400 Watt CMH puts out less lumens than 400 Watt HPS but the spectrum is much more complete. If your grow room has windows providing some natural light which can be put to use, your best choice would probably be HPS or CMH to supplement the natural lighting available to your plants. If your HID lamp(s) will be your sole source of lighting for your plants, you will probably fare best using either CMH, enhanced spectrum HPS or enhanced spectrum MH.

Heat buildup may necessitate ventilation of your grow room or you could use air-exhausted fixtures much like growers of illicit herbs use. This is accomplished by adding a pane of tempered glass to the system/reflector to seal off the bulb. Then attach a flange and fan unit to the system/reflector and use flexible ducting to exhaust most of the heat to another room or outdoors via a ventilation shaft.

The enhanced spectrum MH and HPS bulbs are both pretty nice, especially the Hortilux brand. Hortilux Blue MH provides a broad spectrum of light very similar to CMH but a 400 Watt Hortilux Blue MH lamp doesn't produce as much light as a 400 Watt CMH, isn't rated for as long of a life, and absolutely must be used in a closed fixture (with glass pane). CMH is rated safe for use in open fixtures (no glass pane) as are most HPS lamps.

Hortilux Super HPS 600 Watt may be the answer you are looking for if you want to use no more than 600 Watts and your HID lamp will be your only source of light for your plants (no natural light). The light it produces will look very yellow to your eyes but it does produce useable blue wavelengths in greater quantities than standard HPS lamps. It produces more lumens than either MH or CMH and the lamp is rated for more hours of use as well. All HID lamps should be replaced annually, however, to get the most amount of light from them and to avoid catastrophic lamp failure. I believe the Hortilux Super HPS is also rated for use in open fixtures, but I'm not absolutely certain of this.

Wide shallow reflectors spread light out over larger areas but with less intensity than deep reflectors. Smaller deep reflectors provide more concentrated light but to smaller areas. Deep reflectors help the light to penetrate more deeply into the foliage of tall plants.

Light movers help to extend your growing area without adding more light bulbs. They also work to help avoid hot spots, overly bright spots and overly dark spots and to blend two different light sources (such as HPS and MH) more effectively. They also add expense, complexity and additional maintenance issues to your setup. I'm not a big fan of light mover systems. That's just my own opinion. Other people swear by them.

Others will have to advise on the distance between your type of plants and your chosen light source. My advice for lighting sources would be:

HPS 400w or HPS 600w if your lamp will be supplementing natural light sources.

CMH 400 Watt x 1 or 2 units (Sun System 2 switchable) if you have no natural light sources whatsoever
or
HPS Hortilux Super 600w (enhanced spectrum) x 1 lamp if you have no natural light sources whatsoever and use a wide shallow reflector. You could use a digital remote ballast with the Hortilux Super 600 Watt HPS lamp and have less heat production from the ballast that way too.

Another way to reduce heat in your growing area is to use remotely ballasted light systems. Placing your ballasts outside your grow room and having only the lights/reflectors inside your grow room will negate the heat issue from the ballasts leaving only the heat from the bulbs to deal with. All-in-one systems don't allow this option. All-in-one systems are better for CMH, however, since the wire from the ignitor to the bulb is much shorter in all-in-one systems. CMH bulbs work better with shorter ignitor wires. You might need to ventilate your room or add exhaust systems to your all-in-one fixtures if heat becomes an issue.

A big advantage to using digital ballasts is that they produce less heat than magnetic ballasts. They don't hum either. My magnetic ballasts hum a little bit, but I don't really notice it since they are in the basement. Digital ballasts don't last as long as magnetic ballasts, however, so be sure to buy a good name brand to get the most out of a digital ballast. Cheap brands will burn out quickly.

MH bulbs require closed fixtures (bulbs behind glass). I'd say avoid using MH of any kind unless you're already planning on ventilating the reflectors since doing so also requires the use of closed fixtures.

Lanmark,

thanks again for a lot of helpful info.

The room is in the basement as well with a temp range of 60-70. I doubt heat will be an issue if I stick with a 400/600w system.

One question though. Why does MH require a closed reflector? Does it produce much more heat than HPS?

That SunMaster MH Neutral Deluxe which Ernie mentioned sounds good too, but as he said, I don't know what products are available in Canada. I believe it is an HPS to MH conversion lamp with much the same spectrum as CMH. :clap:

There's almost too much information to process don't you think?! :rollhappy:

As ehanes7612 stated, you must take into consideration the heat and humidity issues created by HID lamps. Don't turn your plants into crispy critters.

Oh, and be very careful to avoid splashing water onto hot HID lamps (bulbs). If splashing is going to be an issue for you, consider using closed fixtures -- in which case I'd say use two 400 Watt lamps (CMH or SunMaster MH Neutral Deluxe) in fan-exhausted switchable Sun System 2 all-in-one fixtures. :wink:

papheteer said:

Lanmark,

thanks again for a lot of helpful info.

The room is in the basement as well with a temp range of 60-70. I doubt heat will be an issue if I stick with a 400/600w system.

One question though. Why does MH require a closed reflector? Does it produce much more heat than HPS?

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Because the lamps are not made in a protected design with an inner envelope to protect you from burning UV light rays if the outer glass bulb is shattered. All bulbs can shatter, but only unprotected type lamps can burn your eyes with UV rays when the outer envelope is shattered. You should find out whether or not any lamp you decide to use is rated for use in open or closed fixtures and act accordingly.

I use CMH lamps in open fixtures (no glass pane) since CMH are protected-type lamps by design and rated safe for use in open fixtures, yet I am still very careful not to splash water onto the hot bulbs. Flying hot shattered glass is still very dangerous, even if intense UV radiation isn't simultaneously spewing out in all directions. I like my skin and corneas too much to risk such types of damage.

Wiki also states:

"All HID arc tubes deteriorate in strength over their lifetime due to various factors, such as chemical attack, thermal stress and mechanical vibration. As the lamp ages the arc tube becomes discoloured, absorbing light and getting hotter. The tube will continue to become weaker until it eventually fails, causing the break up of the tube.

Although such failure is associated with end of life, an arc tube can fail at any time even when new, due to unseen manufacturing faults such as microscopic cracks. However, this is quite rare. Manufacturers typically "season" new lamps to check for manufacturing defects before the lamps leave the manufacturer's premises.

Since a metal halide lamp contains gases at a significant high pressure, failure of the arc tube, is inevitably a violent event. Fragments of arc tube are launched, at high velocity, in all directions, striking the outer bulb of the lamp with enough force to cause it to break. If the fixture has no secondary containment (e.g. a lens, bowl or shield) then the extremely hot pieces of debris will fall down onto people and property below the light, likely resulting in serious injury, damage, and possibly causing a major building fire if flammable material is present.

The risk of a "nonpassive failure" of an arc tube is very small. According to information gathered by the National Electrical Manufacturers Association (www.nema.org), there are approximately 40 million metal halide systems in North American alone, and only a very few instances of nonpassive failures have occurred.

There are measures that can be taken to reduce the damage caused should a lamp fail violently:

Ensure that the fixture includes a piece of strengthened glass or polymeric materials between the lamp and the area it is illuminating. This could be incorporated into the bowl or lens assembly of the fixture.

Use lamps which have a reinforced glass shield around the arc tube to absorb the impact of flying arc tube debris, preventing it from shattering the outer bulb. Such lamps are safe to use in 'open' fixtures. These lamps carry an "O" designation on the packaging reflective of American National Standards Institute (ANSI) standards."

They also recommend using only reputable brand-name lamps (no cheaply made no-name or off-brand imports) and to replace lamps well before their rated number of hours/end of life.

So I guess protected or "O" rated lamps also protect against molten bits of arc tube flying out in all directions in the event of lamp failure and not only against UV burns in the event of outer envelope breakage.

I would suggest looking at another route. Look at HO and VHO flourescents. My basement grow room is 8x8 and 2 400w HPS lights generated too much heat. I have switched to t5HO fixtures and am able to get the same effect without all the heat. Additionally I am able to get the Plants mych closer to the bulbs without the high risk of heat damage.

Lanmark said:

I use CMH lamps in open fixtures (no glass pane) since CMH are protected-type lamps by design and rated safe for use in open fixtures, yet I am still very careful not to splash water onto the hot bulbs. Flying hot shattered glass is still very dangerous, even if intense UV radiation isn't simultaneously spewing out in all directions. I like my skin and corneas too much to risk such types of damage.

Wiki also states:

"All HID arc tubes deteriorate in strength over their lifetime due to various factors, such as chemical attack, thermal stress and mechanical vibration. As the lamp ages the arc tube becomes discoloured, absorbing light and getting hotter. The tube will continue to become weaker until it eventually fails, causing the break up of the tube.

Although such failure is associated with end of life, an arc tube can fail at any time even when new, due to unseen manufacturing faults such as microscopic cracks. However, this is quite rare. Manufacturers typically "season" new lamps to check for manufacturing defects before the lamps leave the manufacturer's premises.

Since a metal halide lamp contains gases at a significant high pressure, failure of the arc tube, is inevitably a violent event. Fragments of arc tube are launched, at high velocity, in all directions, striking the outer bulb of the lamp with enough force to cause it to break. If the fixture has no secondary containment (e.g. a lens, bowl or shield) then the extremely hot pieces of debris will fall down onto people and property below the light, likely resulting in serious injury, damage, and possibly causing a major building fire if flammable material is present.

The risk of a "nonpassive failure" of an arc tube is very small. According to information gathered by the National Electrical Manufacturers Association (www.nema.org), there are approximately 40 million metal halide systems in North American alone, and only a very few instances of nonpassive failures have occurred.

There are measures that can be taken to reduce the damage caused should a lamp fail violently:

Ensure that the fixture includes a piece of strengthened glass or polymeric materials between the lamp and the area it is illuminating. This could be incorporated into the bowl or lens assembly of the fixture.

Use lamps which have a reinforced glass shield around the arc tube to absorb the impact of flying arc tube debris, preventing it from shattering the outer bulb. Such lamps are safe to use in 'open' fixtures. These lamps carry an "O" designation on the packaging reflective of American National Standards Institute (ANSI) standards."

They also recommend using only reputable brand-name lamps (no cheaply made no-name or off-brand imports) and to replace lamps well before their rated number of hours/end of life.

So I guess protected or "O" rated lamps also protect against molten bits of arc tube flying out in all directions in the event of lamp failure and not only against UV burns in the event of outer envelope breakage.

Click to expand...

I guess using an enclosed reflector is the way to go! lol

Darin said:

I would suggest looking at another route. Look at HO and VHO flourescents. My basement grow room is 8x8 and 2 400w HPS lights generated too much heat. I have switched to t5HO fixtures and am able to get the same effect without all the heat. Additionally I am able to get the Plants mych closer to the bulbs without the high risk of heat damage.

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I've considered t5HO fixtures as well (i still do for utilizing the space under the table). The thing is in my basement the temperature rarely exceeds 70F even in the summer so I was thinking the heat from a 400/600w system could be beneficial.