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Sodium vs. Metal Halide Lamps · Hydroponics Daily

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  Hi, welcome back to Hydroponics Daily. Today we're talking about sodium lamps and metal halide lamps.
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  Now, a lot of people think that high-pressure sodiums or HPS lamps are the same
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  as street lamps, the sort of street lighting you used to get before LEDs came
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  along. However, they are different.
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  So, street lights, low-pressure sodiums, and they release an emission just in
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  the orange part of the visible spectrum.
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  So they're the ones that go pink when they first start up and
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  then they go bright orange these aren't used
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  as grow lights you'll you'll never see anyone running grow
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  lights with low pressure sodiums you might you know
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  it would work but your plants would look a bit
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  funny there would be no red light no no blue in the in
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  the spectrum so we use high pressure sodiums and
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  high pressure sodiums were the grow light for decades that's
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  because they produced a good spectrum for plant
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  growth not as good as sunlight but pretty pretty still pretty good not a massive
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  amount of green like you get with the fluorescence so there's good red good
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  blue and not too much far red and they were compact they produce a lot of light
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  from a very small area and so they heat up a.
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  Sodium in there and it ionizes and it produces a
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  wire spectrum and under high pressure they get xenon
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  gas in there as the starter gas and you
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  needed a ballast with them so an old
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  style grow lamps used to weigh an absolute ton
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  and were really heavy and the
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  new ones that have come out in the last say 10-15
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  years are much lighter however they they're still
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  pretty big they still require this big ballast and much
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  bigger than the ballast on a fluorescent lamps and so that's something
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  to consider you screw them in to the to the
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  ballast and you have to make sure you use gloves or paper towel as you're screwing
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  them in because you're the grease on your from your skin can affect and the
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  lifespan of the sodium lamps you have to keep them clean dust free because any
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  any contamination on the bulb will affect their.
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  Lifespan and you also have a reflector to because
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  it's obviously producing light in 360 degrees and so
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  you reflect that back down into your plants and so you would
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  these were used in in both grow rooms and in.
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  Industrial units and glass houses
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  and they the other thing is they produce a lot
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  of heat so they were moderately efficient compared
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  to other types of light and they but
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  they also produce this heat and this heat this infrared light was
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  good at stimulating plant growth and so it drove transpiration.
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  The the as it heated up the leaves so it
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  provided a heating effect as well and so people move towards more
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  efficient lights like led lights they've they've
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  sometimes they don't factor in the fact that your plant
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  may have needed that direct infrared heat from
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  the from the sodium lamps so a lot of growers still use
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  sodium lamps especially greenhouse growers because they
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  need they need the heat and the cost of
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  changing all the electrical electrics and
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  putting in led lights is significant
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  so lots of people still use sodium lamps especially large
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  growers if you're a hydroponic grower growing
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  in a grow tent i would only use high pressure sodiums in
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  the winter the amount of heat produced in the summer would just make
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  cooling too expensive and you just want to moved to leds leds
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  are so cheap now that for summer summer indoor
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  grow room growing it's the best option so i said the that's sodium lamps good
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  spectrum not mainly in still even though they're they're different to the low
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  pressure sodiums they still got a good high level of yellow and orange in that
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  in that in that spectrum and then mercury vapor light they're Actually.
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  Metal halide lamps, similar sorts of technology, produce a fairly similar spectrum,
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  not massive amounts of red.
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  Again, in the yellows, a fair amount of green. I think they're used more in
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  America than they are in the UK.
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  In hydroponics, they seem to be popular, metal halide lamps,
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  but in greenhouses, I think sodium lamps are more popular.
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  Certainly gives a sort of truer white colour than sodium lamps.
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  So sodiums still have sodium lamps, even though they're high pressure,
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  they still have that orange tint,
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  everything looks orange whereas a metal halide lamp looks much whiter.
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  And as I say, they've,
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  now you'll they will be less available
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  and than they were because leds are taking over
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  so you might even though you might want to run a metal halide
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  or a sodium lamp you might find their availability
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  diminishes that's because the factories
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  that make them are are shutting down so low
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  so low pressure sodiums the light the lights
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  that you used to see as street lamps the there was a big
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  factory in hamilton in scotland and that's
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  now closed down which is a shame for because it's it's
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  not got that much going for it really the football team's rubbish and
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  it's not the nicest place in the world so yeah shame
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  that there's they've closed the factory down they couldn't move to led
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  lights high pressure sodiums i think are still made but not
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  as much and the problem was is that phillips and osram and
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  companies like that that made them they didn't really want to
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  innovate they were selling enough of these products into warehouses that
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  they weren't really innovating for grow lights so they weren't optimizing.
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  The the spectrum for grow lights because they
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  think well you can just suck it up we're the
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  people who have the monopoly on lights if you want
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  high pressure sodiums and metal halides we're the
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  ones that make it you have to get what we do and so they might repackage them
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  and put special branding on them say you know special grow
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  light but they were often the same grow lights that were going into warehouses
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  and industrial units and outdoor lighting
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  and things like that so they had it good for a long time these
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  companies and then led lights came along and the
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  small manufacturers could modify the spectrum
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  and dramatically and so
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  they were caught on the back foot they couldn't really start innovating because
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  they were an established brand and so that's what another reason
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  why sodium and metal halides went out
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  of business also one of
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  the disadvantages compared to fluorescent lights is because they
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  produce so much heat you can't put any plastic
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  films over them to modify the spectrum so if
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  fluorescence certainly i used to do this you could get far
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  red absorbing or red absorbing films so you can modify the red to far red ratio
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  in your grow room and you could put them over the fluorescent lights about five
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  centimeters off the light and just cover the entire light that was and so the
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  light received by the plants had a much modified spectrum you can't do that with the fluorescent.
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  So you can't do that with a sodium because it would just burn the film
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  it would just melt so that's one disadvantage so that's
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  been hydropanics daily for today not my specialist subject but
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  if you probably know more about metal halide lamps than me i'm not
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  an expert i've never used them to grow plants but i have used high
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  pressure sodiums again just like
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  fluorescents do contain a small amount of mercury so if they smash above your
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  crop then the dust that comes down could contain mercury so you don't want to
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  be consuming that crop tomorrow we'll probably cover leds if i have time to
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  research it thank you very much for listening please like follow share do all
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  that good ones and i'll see you again tomorrow goodbye.