High Pressure Sodium Lamp

[Evil Genius]

Hi Guys! Has anyone experience with these lamps? If so, please let me know about it! I´m thinkin about buying one for my cactus seedlings but i´m unsure if it might nuke them! I´m particularly interested in Tips and Tricks! Do´s & Donts! Limitations and Risks! Are these lamps able to burn down the block? And as i´m usually broke, how expensive can these lamps get at max if i´d use them to overwinter my tropical plants! Can i get a sunburn from working under the lamp? bye Eg

edit: oh and most importantly, what happens if the lamp gets damaged! Is sodium in a high pressure lamp dangerous? Maybe when inhaled?

Edited November 14, 2008 by Evil Genius

[Stonehenge]

I've used them also metal halide. I'm not sure which would be best for cacti. They both put out more light per watt than even a floro which is much much better than incandescent. Never use an ordinary light bulb for plants. How big a one depends on how much space you are going to use. If a 4' x 4' space, you might get by with a 175w or a 250.

They are safe, just do not pour water on them or chew on the electrical cords. Common sense will work. I've had them burn out but never a problem. There is nothing poisonous inside that I'm aware of. If the outer glass breaks, discard the lamp and get a new one. It will still work but the outer glass blocks any UV light and if it's not in place, you could get a UV burn from it. It is hot so don't touch the lamp (bulb) with your hand or anything else.

[Chiral]

Hi Guys! Has anyone experience with these lamps? If so, please let me know about it! I´m thinkin about buying one for my cactus seedlings but i´m unsure if it might nuke them! I´m particularly interested in Tips and Tricks! Do´s & Donts! Limitations and Risks! Are these lamps able to burn down the block? And as i´m usually broke, how expensive can these lamps get at max if i´d use them to overwinter my tropical plants! Can i get a sunburn from working under the lamp? bye Eg

edit: oh and most importantly, what happens if the lamp gets damaged! Is sodium in a high pressure lamp dangerous? Maybe when inhaled?

Absolutely stay away from being under the lights with your arms and neck and head etc..these lamps can cause skin cancer and can burn the shit outta you. If you have to work around or near the light turn it off and let it cool then use a torch or normal room light to work. Don't... and I mean it..! spend any time under these lights..not even 5mins..5mins every other or every day is enough to fuck with your skin..trust me I know. The other sucky thing is the electricity bill especially when left on for the vegetative stage. Just take precautions be safe with them and don't take any risks. Use chain to hang so as you can adjust height as necessary so as crops don't get too close and burn. Keep the wings and surrounds clean and don't let dust and crud build up around the lamp as it can cause fires. Make sure there is adequate air circulation to keep the efficiency of the lights at their optimum. Use a timer to turn off and on so as the times are daily equal. Another thing to watch is mould and fungus build up..keep the air flowing and regularly clean around the pots and bases and walls etc..Spider mites are your usual pain in the ass pests when using lights so use predators to catch them. mmm that be it I think enjoy.

Enjoy.

H.

[Evil Genius]

these lamps can cause skin cancer and can burn the shit outta you.

who hooo, glad that you mentioned it! Do you think that even indirect light might be able to cause skin cancer? I can only put the lamp in one particular room and it´s not possible to close the door! So i get in contact with indirect light from time to time! Do you think that might be a Problem?

[Chiral]

No that should be ok, as long as its not for extended periods daily..should be ok..its the direct light that's a concern..I learnt the hard way after spending hrs under 6 lights for extended periods I appear to have done irepairable damage.. learn from others mistakes is a good policy.

H.

[Plantsoma]

I used a 600w HPS lamp in a laundry to keep my cacti kicking over winter when i was living in the cold mountains.

I didn't realise they were so nasty on the skin Hunab. I just thought it would be the equivalent of a hot summers day. God, i used to enjoy going in to water them after work because of the warmth and it was 2deg outside. Whoopsie.

The cacti seemed to love it, none got burnt or were close to the light and they grew amazingly.

[Evil Genius]

Thanks Hunab! I´m good at making mistakes myself so i might be able to return the favour one day! :-) I´ve decided to buy the lamp! I´ll post more later! bye Eg

[Sassy]

The other thing to be aware of is burning ones eyes . I have used these lights in a chamber ,too small to get in and burn skin, but , if you get stoned and watch plants grow , like someone did , you may wake up later that night with a feeling someone is trying to gouge out your eyeballs with a mixture of sand and salt , aka Welding Flash or sunburnt eyes.

[hela]

For cacti seedlings I'd suggest trying a T5 or T8 fluoro setup before using the HID stuff. They use lots less electricity and are easier to setup/handle. Plus a HID lamp is sorta overkill for cacti seedlings. They enjoy lots of light and a fluoro bulb is perfect.

[Stonehenge]

Floros are a good substitute. I don't agree that they are that dangerous on the skin. I have not had any such problems. Do you burn easily in the sun? Does that give you problems after even 5 minutes? If not, then don't stress. There should be less UV than from the sun since the outer quartz glass blocks most of it.

I do agree it is not the best for your eyes. I use a pair of sunglasses when I'm using one. Anything should do, I use wrap arounds that are rated to block all UV. Ones with a light color should be good. I should have mentioned that before.

[Chiral]

Floros are a good substitute. I don't agree that they are that dangerous on the skin. I have not had any such problems. Do you burn easily in the sun? Does that give you problems after even 5 minutes? If not, then don't stress. There should be less UV than from the sun since the outer quartz glass blocks most of it.

I do agree it is not the best for your eyes. I use a pair of sunglasses when I'm using one. Anything should do, I use wrap arounds that are rated to block all UV. Ones with a light color should be good. I should have mentioned that before.

What reason would you have to say such things..are you working under them everyday and getting a lovely tan....I don't understand why you would say such a thing when I have clearly given Evil Genius such sound safety advice..if you want to see the damage they can cause I'll gladly send you some pics of my skin cancer all on my right side of my body from where I was an idiot and spent countless hrs leaning in and across under these lights to manicure and manage fast growing plants.

H.

Edited November 15, 2008 by Hunab Ku

[Evil Genius]

Hi Guys! Thanks for your help, yall!

Ok, got the lamp today and its brighter than the sun! Shit fucking shit!

Hunab, what kind of Lamp did you use? According to the Lamp Guy, a HP Sodium Lamp doesnt emmit UV Rays but Metal Halogen Lamps do! Is it possible that yours was a Halogen Lamp? They are known to cause sunburn and cancer! In any way, i will stay away from direct light!

Another Problem arose today! The lamp was running for about 5 hours and then i recognized a weird chemical smell! Is it possible that the lamp is nuking my PP Pots and dishes? Actually i thought that they should stand these temperatures! All of them are food approved! Any idea what kind of chemicals might be gasing out there?

[Chiral]

must have been halogen I was using..damn it was 8 yrs ago and my mind is shot I can't remember..the smell might just be the lamp.. as its new it might be just the smell of it...by the way you should never handle the lamp its self with bare hands always use alcohol swabs to handle them otherwise small spots of oil from your skin will collect on the lamp and burn and shorten the life of the lamp dramatically.

H.

edited for typo's

Edited November 16, 2008 by Hunab Ku

[Plantsoma]

Metal Halide (MH) is the really white light.

High Pressure Sodium (HPS) is a very yellow light.

Are halogen the same as MH?

Edited November 16, 2008 by Plantsoma

[Chiral]

Halogen produces a whiter light and color than standard incandescent lamps. Brighter halogens allow you to use lower wattage lamps to achieve the same levels of illumination as were provided by higher wattage lamps, thus substantially saving on lighting energy costs.

Metal Halide lighting is a type of High Intensity Discharge (HID) lighting. Other types of HID are Mercury Vapour, High Pressure Sodium and Low Pressure Sodium. All HID lamps work on the same principle, that of causing an arc across a gas or vapour and using the gas or vapour as a conductor, the same way incandescent lamps use a tungsten filament as its conductor.

Prior to the Metal Halide Lighting system most HID type lighting was used outdoors. This is due to ballast noise and the ill effect this type of light has on colour. The Metal Halide has reduced the excessive noise and has improved on the colour effect, especially at the red end of the spectrum. With these improvements, Metal Halide is being used more and more for indoor applications including gymnasiums and in low ceiling warehouses. However, Metal Halide is not without its problems, specifically extreme heat and the possible emission of ultraviolet rays. These two faults have proven to be a Health and Safety concern for workers. When fully lit, the Metal Halide lamp will reach a temperature of 2000 degrees Fahrenheit and operates at a vapour pressure between 70 and 90 pounds per square inch. Normal use of Metal Halide lighting requires that they are very rarely, if ever shut off. The constant heat takes its toll on the glass of the inner and outer cone, causing them to deteriorate and possibly break.

When the lamps break, extremely hot fragments will fall to the ground, possibly landing on workers or combustible materials. Millions of dollars in property have been lost because of the fires caused by Metal Halide lighting, but more importantly there have been serious burns/injuries to workers. (Saskatchewan, 2004)

Another danger of these lamps is the possibility of the leakage of Ultraviolet Rays. Again, after long use and the deterioration of the inner cone, the lamp may develop cracks. Ultraviolet rays can leak through these cracks. For workers, the danger is that the rays can cause burns (similar to a sunburn) or skin irritation, when exposed over a period of time. Another area of concern are the workers' eyes. The contact of the ultraviolet rays with the eyes over a period of time could be compared to that of a welding flash, however, is not as intense but equally damaging and painful. The dangers of this method of lighting can be reduced by regular replacement and maintenance. One method of maintenance is to shut the lamps down once a week for fifteen minutes. This will allow the lamp to cool. If it is damaged or deteriorated, the lamp is less likely to re-light.

What is the difference between High Pressure Sodium and Metal Halide?

The difference between these two types of HID (High Intensity Discharge) lights is the color spectrum that is emitted from each. The High Pressure Sodium bulb emits light that is concentrated in the red to yellow side of the spectrum and are weak in the blue-violet end. While the Metal Halide bulb emits light that is very balanced and contains all the energy peaks at wavelengths of the visible spectrum. Visually the Sodium bulbs will appear very yellow-orange and the Halide bulbs will appear more blue-white in color.

Should I use Sodium or Halide?

The Halide lights have a very balanced spectrum and are excellent for vegetative growth or leafy plants like lettuce and basil. The Halide lights produce between 65-115 lumens per watt which is a measure of the efficiency of the bulb, or how much light you are producing for the amount of electricity you are using. The Sodium lights produce light that is very bright and concentrated on the yellow to red side of the color spectrum. This color is not as balanced as the Halide but makes up for the lacking of a balanced spectrum in the amount of light given off by the bulb. The Sodium bulbs produce between 97 to 150 lumens per watt which is much higher than the Halide bulbs. The Sodium bulbs are superior in life expectancy and efficiency while the Halides a superior in spectral distribution so your decision will be based on what is more important to you.

Why do people use Metal Halides for vegetative growth and High Pressure Sodium's for flowering?

Many people switch between bulbs for different stages of growth for a couple of reasons. First of all, Sodium bulbs have been known to make some plants grow leggy and stretched out because of the yellow to red spectrum that they give off. Metal Halides tend to keep these plants tighter with less space between internodes. So some growers use the Metal Halide lights during vegetative growth to keep the structural growth of the plant nice and tight. But they switch to Sodium lights when the plants begin to flower because the Sodium lights produce so much more light than the Halides. Even though the Sodium's do not have as good a spectrum as the Halides the intense light that is put off by the Sodium's aids in flower development and fruit set. Do not be fooled though, you can use either light throughout the life of a plant and get excellent results.

I pulled some of this off the nerdnet..I also found some info that HPS lamps do emit some UV rays but very little in comparison to Halides..I remember now I was using Halides for the job I was doing as they are the superior all round light and I remember them being very white almost blue in fact.

H.

[Evil Genius]

Hi Hunab! Thanks for the detailed info! This helps a lot! bye Eg

[blog]

This picture shows the limitation of sodium lights. Photosynthesis really does want blue light, sodium only gives it some red spectrum. I remember reading some nasa study about growing plants in space and the most efficient way of doing it. The recommendation was for 2 highly efficient lights, one red and one blue.

edit, found something that relates to what I read.

Red light-emitting diodes (LEDs) are a potential light source for growing plants in spaceflight systems because of their safety, small mass and volume, wavelength specificity, and longevity. Despite these attractive features, red LEDs must satisfy requirements for plant photosynthesis and photomorphogenesis for successful growth and seed yield. To determine the influence of gallium aluminium arsenide (GaAIAs) red LEDs on wheat photomorphogenesis, photosynthesis, and seed yield, wheat plants were grown under red LEDs and compared to plants grown under daylight fluorescent (white) lamps and red LEDs supplemented with either 1% or 10% blue light from blue fluorescent (BF) lamps.

Compared to white light-grown plants, wheat grown under red LEDs alone demonstrated less main culm development during vegetative growth through preanthesis, while showing a longer flag leaf at 40 DAP and greater main culm length at final harvest (70 DAP). As supplemental BF light was increased with red LEDs, shoot dry matter and net leaf photosynthesis rate increased. At final harvest, wheat grown under red LEDs alone displayed fewer subtillers and a lower seed yield compared to plants grown under white light. Wheat grown under red LEDs + 10% BF light had comparable shoot dry matter accumulation and seed yield relative to wheat grown under white light.

These results indicate that wheat can complete its life cycle under red LEDs alone, but larger plants and greater amounts of seed are produced in the presence of red LEDs supplemented with a quantity of blue light.

Edited November 18, 2008 by blog

[DreamingNagual]

I think I remember Grow Australia Selling Dual Spectrum Globes!

Anyone tried these?

Supposed to have double the effective life than Normal HPS or MH!

[Stonehenge]

HK, I'm sorry about your skin cancer but I doubt it was from an hps lamp. As I've said repeatedly, they put out very little UV. Your quoted sources say the same thing. What is the controversy? Then you said it was from a halogen lamp?

Either hps or mh will grow plants just fine. The only difference I've seen is that the hps produces slightly shorter bushier plants and the mh may cause them to stretch a little more. Either or both together work fine for growing plants. I've done it.

Bright light of any type can be bad for the eyes. That's why I used the sunglasses. Going in the sun for a few minutes gives you more UV exposure than twice the time under the lights.