Bit lost in the Luminaire Jungle, new Project

Discussion in 'Lighting' started by eoto, 2 Jul 2009.

  1. eoto

    eoto Member

    Messages:
    29
    Location:
    Munich
    Hello Folks,

    im looking for a Luminaire for my new Project, few Facts here.

    Tank Size: 60 x 30 x 36 cm, 60 Liter
    Will be an Iwagumi so mostly only one Plant like HC, Glosso maybe add an other one but maxium 2 Plants.
    2x24W Lighting T5 (might be fine for that Tank, correct me if im wrong)

    So what should i go for? The Arcadias seem good but theyre not that cheap.
     
  2. Dave Spencer

    Dave Spencer Member

    Messages:
    1,389
    Location:
    N. Wales
    Try EQJ Trading on eBay.

    Dave.
     
  3. samc

    samc Member

    Messages:
    1,381
    i have a fluval osaka luminaire which is 2x24w which i picked up on ebay for £20 posted so keep an eye out as there are some bargains on there
     
  4. Nelson

    Nelson Member

    Messages:
    2,583
    Location:
    Norfolk
  5. davidcmadrid

    davidcmadrid Member

    Messages:
    115
    Has anybody tried these luminaires ?
    http://cgi.ebay.co.uk/T5-AQUARIUM-OVERH ... 1|294%3A30 . They are sold as Marine with 10 K kelvin bulbs and they sent me the follwing chart for output. The legs are plastic and not metal but the spare legs are cheap so perhaps worth having. They also do a kit to hang it over the tank for 26 pounds.

    2009-07-10_1721.png
     
  6. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    All that chart tells you is that the light will more than likely be bluish rather than yellowish. If the legs are strong and well built there shouldn't be any problems.

    Cheers,
     
  7. Nelson

    Nelson Member

    Messages:
    2,583
    Location:
    Norfolk
    hi david,
    i've got one.hailea,all the way from china :lol: .i had a problem with two tubes not coming on.they/brett sent a new switch first.not switch.so he replaced it no problems.also broke one of the legs :rolleyes: was before they had new sets available so he sent one from another box :D .
    ok since then,april.
    did get new tubes from http://www.lampspecs.co.uk/Light-Bulbs- ... 8Ta38Pchn0

    i would say not the best quality but ok.cheap and cheerful :lol: .
    also only one power lead.
     
  8. davidcmadrid

    davidcmadrid Member

    Messages:
    115
    I thought you could get more from spectral analysis than a determination of the colour of the light ( which comes from the Kelvin value ) ,, specifically you could find out how much light is sent out in the frequencies at which plants like to photosynth at best ? Im referring to this article http://www.aquaticplantcentral.com/forumapc/lighting/38014-lighting-spectrum-photosythesis.html I was thinking the blue and red are good for plant growth and the green spike would be good for giving the plants a bright green enhancing look.
     
  9. davidcmadrid

    davidcmadrid Member

    Messages:
    115
    Nelson,

    Thanks , the legs are the bit i was worried about ( so was thinking about hanging it instead ) do you find any flicker with it ( know the ballast type ? ) and aside from the legs do the reflectors and build quality seem good. I am still looking about here but it seems this , the T5 hagen glo or the Arcadia jobby. Appreciate the feedback.
     
  10. Nelson

    Nelson Member

    Messages:
    2,583
    Location:
    Norfolk
    hi david,
    they did flicker a bit when i first got them.not anymore though.don't know the ballast type,i guess no name chinese.
    reflectors seem ok.build quality ok,not great.
    if you've got the money get an arcadia.
     
  11. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Well it's a very nice article with tons of very good information in it. Unfortunately, the author misses a key point that render spectral analysis redundant. Plants manufacture what is known as "auxiliary" pigments which, when struck by non primary colors, transfer their energy to the primary pigments such as Chlorophyll A, B and so forth. In this way plants can use whatever spectral quality is available in that particular environment since they have no choice in the availability. The spectral quality of the ambient light in any natural environment changes dramatically from dawn to dusk, reddish/yellowish at the endpoints of the photoperiod and blue/violet during the middle part. Many plants even get shaded and are only able to absorb within a restricted gamut of colors based on reflections and so forth. There are even very harmful wavelengths, such as UV which the plants must develop pigments to reflect (or convert) in order to mitigate damage to cell structure. There is potpourri of various pigments that act as light absorbers, light converters and light reflectors and these pigments develop based on the existing conditions. So no matter what bulbs you use, the plants will adapt to the spectrum provided by developing the necessary pigmentation to optimize growth and food production. One bulb therefore grows plants as well as any other simply because of the adaptations that the plants make.

    It is not really a valid notion that somehow, only algae "like" wavelengths in the 500/600 range. I can assure you that algae will form just as easily under any wavelength based on the algae trigger mechanisms of photon flux density and other environmental factors. A lot of this data comes from marine studies which show that symbiotic phytoplantonic life forms (many of which are algal species) are adapted to ocean depths where most other wavelengths are absorbed except for blues. This data is then extrapolated to freshwater environments where they may not be as valid.

    Many people assume that because plants look green then it means that they do not use green wavelengths but they forget that a plant can reflect a combination both yellows and blues, which, when those wavelength combinations reach our retina, our visual cortex perceives as green. So just because plants look green it doesn't necessarily mean that they are green. There's plenty of photon energy in all visible wavelengths and plants have amazing adaptability. One should therefore get bulbs that have a spectral quality that you find pleasing, and not worry about what is "optimum" for plants. This is yet another method of propaganda that vendors use to charge high prices for bulbs. Your plants will grow just as well with 10,000K marine bulbs as they will with bulbs from Tesco. The only difference will be whether you find the light pleasing or not. In fact if you study the latter portion of that article you'll see that the author is saying the very same thing actually.

    Cheers,
     
    Victor likes this.
  12. davidcmadrid

    davidcmadrid Member

    Messages:
    115
    Is that less efficient ?
     
  13. GreenNeedle

    GreenNeedle Member

    Messages:
    2,706
    Location:
    Lincoln UK
    No idea but thats nature :)

    At the end of the day you bought a luminaire. The manufacturer sent you a chart showing you what the tubes do. You will replace the tubes eventually.

    AC
     
  14. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    That's right. And besides, the photosynthetic efficiency of plants is already extremely high.The difference in growth and food production is not going to be seen in real terms. There are a lot more things that will have direct and palpable differences in the growth of your plants. A simple adjustment of CO2 injection rate will have far greater consequences than any differences you'll see by trying to optimize spectral efficiency, that's for sure. Can any bulb maintain it's spectral output over a few months? No chance. They start to degrade/shift almost immediately. Think about all the various reflections and spectral changes from substrate, neighbouring plants, and even from the surface. Chasing spectral efficiency or optimization for a planted tank is another illusion of The Matrix. Concentrate more on CO2, nutritional requirements, flow and maintenance and you'll reap very real and substantial benefits.

    I'll mention something else about those spectral charts. Do you see where those peaks are? Vendors try to convince us that, for example having a red peak actually means that you get a substantial amount of red, which is of course, hogwash. These are simply individual wavelength energy readings. It's the area under the curve that has meaning because each wavelength adds photons as they strike the chloroplast. So you have to look at the sum total of the wavelengths to add all the photons together. Look at the area under the blue. Even though the blue peak is a lot lower than the green peak, the amount of blue/cyan photons striking the chloroplast molecules are much higher then the number of green or red photons striking them. A single high peak is completely meaningless. So this bulb has mostly blue energy, which we would see as being dim, because we are not very sensitive to blue. The green level is used as probably a "luminance" level so this peak allows the bulb to appear even brighter to us, but it is still useful energy for the plants. If that green mountain were wider, the bulb would appear very bright to us because our eyes are optimized for sensitivity around that wavelength.

    Each time a single photon strikes the chloroplast a single electron is liberated from it's orbit due to added energy. Since blue is a higher frequency more blue photons strike the chloroplast per second than green or red photons whose waves strike at a lower frequency. So the fundamental energy level of blue radiation is higher and it delivers more photons per second.

    Blue energy, in general, stimulates amino acid production (which are later assembled into proteins). Red light, in general, stimulates glucose/sucrose production. Ultimately, it is the number of photons striking the chloroplast per second that powers plant life. Each strike moves electrons and it is these electrons that are used in the various chemical reactions of photosynthesis. The plant regulates and allocates the pigments to perform whatever functions necessary manage the electron flow without any optimization schemes from us. Control the level of photon flux, i.e the wattage, and you will have done your part. Leave spectral efficiency to the plants. They will figure it out.

    Cheers,
     
  15. davidcmadrid

    davidcmadrid Member

    Messages:
    115
    Hi,

    I havent bought the luminaires yet, I am just looking into this at the moment before ordering them for the tanks. Im learning and unlearning. When i first put plants in the tank years ago the they all didnt look so great after a while. The shopkeeper told me it was because we had a tungsten lamps in the tanks so gave m the mindset that the type of light was important. Im sort of of the mindset now that it was nutrients lacking when i think about it.
     
  16. davidcmadrid

    davidcmadrid Member

    Messages:
    115
    Thanks Ceg 4048, very interesting reading. I can see now also how from the spectral graph you can take a stab at the kelvin value of the bulb. In this case the Blue portion of the bulbs spectral graph contains most of the volume so the energy appears low frequency or high kelvin ? This implies that contrary to what is propogated in the lfs kelvin and frequency are linked?
     
  17. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    Messages:
    8,953
    Location:
    Chicago, USA
    Yes, false correlation is the single most insidious flaw of this hobby. There are many variables which contribute to plant health, and indeed the health of the tank as a system. You can do something today and not see it's effects for a week, the day after you do something completely unrelated. It then becomes easy to blame the unrelated action for the effects observed. That's why we have to adopt the mindset of being systematic and to question the results until we can reliably and repeatable produce those results to draw valid correlation between cause and effect.

    Frequency is the inverse of Wavelength (F=1/W and W=1/F). Blue light has a low wavelength therefore it has a high frequency. The energy of radiation is inherent in its frequency, which, when you think about it make sense. The more frequently something hits you the more damage it will do. As the wavelengths get shorter (frequency gets higher) you'll find that we move out of the visible spectrum and into progressively more seriously damaging radiation. UV then X-rays, then Gamma rays which will fry you to a crisp, even though you can't see them. A photon energy packet rides on each single wave, so a single ray of green wavelength, say of 500 nanometers (500 X 10E-9) would deliver about 2 million photon packets per second, but a single ray is actually composed of two individual rays which are perpendicular, so this means 4 million photon packets per second per ray. When you increase the wattage you increase the number of individual rays. The way that a plant "sees" light is not as a continuous "glow" but as a cosmic hailstorm of photon torpedoes and at the same time as ocean waves crashing against rocks. Too much light actually can cause damage and can curtail photosynthesis. This is called photoinhibition.

    As far as the apparent Kelvin temperature, check that APC link again at the C.I.E chromacity space map. You'll see that as the theoretical black body heats up, the color changes from a red glow, to white hot, to blue hot. So red is a lower Kelvin temperature, a lower frequency (higher wavelengths) and thus a lower energy level, while blue represents a higher energy level, a higher frequency (lower wavelength). So a 10,000K bulb should appear whitish/bluish, which is consistent with the higher blue/violet/cyan space depicted on the spectral graph you provided. Whether the bulb will actually show that is another story, but that's what is should show theoretically. Again, for the marine reefer types this probably has much higher relevance since their symbiotic Zooxanthellae, which do photosynthesise are finely tuned to specific spectral qualities, or at least their visible pigmentation is. Whether this has an effect on food production I can't say.

    In any case, yes, that's all I did was to look at the relative color areas and then to take a stab at what it ought to look like.

    Hope this makes sense.

    Cheers,
     
  18. davidcmadrid

    davidcmadrid Member

    Messages:
    115
    Yes it makes sense , wavelength being the inverse of frequency, been a while since i used my physics :D Out of curiosity what lumens value .. since i gather WPG is kind of defunct depending on the efficency of the bulb 15W in one is not the same in the other e.g. t5ho @30 W gives more light / photons than a T8 at 30w ? is considered to cause photoinhibition ? I believe you could go into lux or PAR and what not but a rough guide , is there something to update the WPG rule of thumb ? Eg lumens per gallon ¿ I am thinking of leaving the existing 2xt8s ( no reflector ) at the back of the tank and putting twin t5hos 2x39w with the Hagen glo reflectors at the front ( thinking that as im going to aim for a carpet the stronger lighting is needed at the front ). I did experiment with a 70 liter tank firing an ungodly amount of light into it ( upwards on 180 +W 5000K studio modelling lamp ) dosing EI ( no fish ) and it looked almost like a fizzy drink there was that much pearling from some plants but slight problems in others ( brown spots on one in particular ) with some others showing nutrient deficency ( Mg ) if i did not keep up. I could never find out what the brown spots were ( not diatoms there was no algea in the tank at all i believe ) . so I am guessing you really have to put a lot of light into the tank to reach photoinhibition,, is there a buffer between useful light and photoinhibition. where its just a waste of light before you start killing things ?

    I am not having any algae problems save 1 spot in the main tank at current light values ( appx 1.3 WPG with T8s ) , so i installed the second filter which now has the lot swaying and cut out the effected leaves and at the time i introduce the higher light i will also be using an external reactor for CO2 on the main filter. Then im going to start trying to tame the jungle and recape the tank.
     
  19. GreenNeedle

    GreenNeedle Member

    Messages:
    2,706
    Location:
    Lincoln UK
    A better model of calculation based on actual PAR values is being worked as we speak but may take a few months to assimilate as the input is coming from many sources. It will not be highly accurate because it will of course not be able to take into account differences between ballasts, reflectors etc. It should basically be a rough guide that a Tn tube of nW will give PAR of n at n distance etc.

    It will however be much better than the WPG rule.

    You shouldn't really enter into the Lumens argument. Although manufacturers push the Lumens count as a marketing tool to sell tubes to you and I that is of no real consequence over the aquarium. Possibly even less accurate IMO than the WPG rule. Lumens are the human's perception of brightness. A manufacturer will tell us our lamp has a third more lumens than our competitors. We take it home and indeed it is brighter. Doesn't mean it has a third more PAR though. It doesn't mean it has as much PAR even.

    LEDs are a fine example where per watt the Lumens are much much lower than flouro. They are substantial amount lower than MH. However they produce much much PAR then both of them.

    A case of watch this space but the work is being done and is long overdue ;)

    It is currently looking like rather than trying to blast sections that have supposed 'highlight plants' it is better to try and get as even a spread as possible and as many seperate light sources as possible which is why LEDs work so well.

    In Flouro terms it means that 4 T8s would be better than 2 T5HO. That would not mean a higher PAR but less hot spots and less dead spots within thetank.

    AC
     
  20. davidcmadrid

    davidcmadrid Member

    Messages:
    115
    Thank, didnt realise i was entering an argument :D Just roughly trying to gauge by adding t5hos x2 how much more light i was adding as I deducted relatively speaking that I was adding more juice with T5hos than t8s of the same wattage. Im not into it enough to get a PAR meter :wideyed: but roughly speaking trying to gauge things. My first " Scape " is going to be a " copy " of somebody elses , reverse engineered just to kick me off which will have a kind of mountain at the back growing up and hopefully forward a little bit so my idea was to shine the Hagen Glo towards the rear a little bit with it sitting on the front of the tank. My laymans idea is that will prevent one plant crowding the other out for light and produce healthy growth vertically through the front of the vertical extent of the plants. One of the things i noted moving the lights around in my experimental tanks was that certain plants seemed to want to grow towards the light and i could put bends in the stems if i played tricks with the plants ) i also know that this is unstable light so can bring on algae on the leaves depending on the type of plant leaf) . Tom Barr said that plants grow towards to the surface to find CO2 abundance but it seems to me that as they cant sniff where the CO2 is they assume its at the light source and grow towards it. Your notion of creating balance gives me pause to think more about that plan.

    But yes I do get the idea that the manufacturers are doing their best to create a standard whilst at the same time trying to figure out a way of saying mine is bigger than yours. Any idea on what Kelvin Value humans percieve as the strongest?
     

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