Lighting In the planted Aquarium

Discussion in 'Tutorials' started by aaronnorth, 13 Jul 2008.

  1. aaronnorth

    aaronnorth Member

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    LIGHTING

    Lighting is very important in plant keeping, i have written this guide in hope to answer some of your questions, please ask in the Lighting section for more accurate details specifically for your tank.

    LIGHT LEVELS
    In an aquarium with a depth of 24”/ 60cm or less, standard aquarium lighting can be used and the ‘Watts per Gallon’ (WPG) rule can be used effectively. This rule is worked out in US Gallons, an example of this:
    Total Wattage/ Total US gallons = WPG
    200w/ 100 = 2WPG

    If an aquarium is deeper than this then more light is needed in order to penetrate to the bottom. Please note the WPG is a rough guide to your lighting levels and is based on T8 Tubes. With the more powerful T5 tubes, which most planted tank enthusiasts use - due to the ability of fitting more tubes over tank and the fact that they produce more lumens per watt - the WPG rule is more leanient and therefore not as much watts are needed for the desired level of WPG that you want.

    0 to 1 WPG – Very Low
    1 to 2 WPG – Low to Medium
    2 to 3 WPG – Medium to Medium High
    3 to 4 WPG - Medium High to High
    Over 4 WPG – High to Very High

    In a tank over 70 US Gallons the WPG rule is more leanient (in other words you don’t need as much light), In tanks less than 10 US gallons more light is needed, take a look here for an explanation on minimum light threshold:

    http://www.rexgrigg.com/mlt.html

    PLANT LIGHT REQUIREMENTS

    Different plant species require different light levels. In General, you can tell the light requirement of a plant by looking at its leaf colour. Darker green plants normally require less light as it indicates that the plant has lots of chlorophyll making it more efficient at photosynthesising. Lighter green or red plants have less chlorophyll making the plant less efficient at photosynthesising therefore requiring more light. One should use these differences in light requirements when planning the overall layout i.e. “lower light” plants should be shaded by the “higher light” plants. Examples of plant species that grow in the very low to low lighting bracket include Anubias, Cryptocoryne, Java fern and various mosses. This said, most of these will still benefit from more light.


    TYPES OF LIGHTING

    There are many types of lighting, there is the T12 fluorescent (1.5” diameter), the most commonly used is the T8 (1”) then there is the T5 (5/8th”). T5 come in HO (high output) and PC (power compact), this allows for deeper penetration in the tank, useful for tanks above 24"/ 60cm. And the relatively new concept lighting - the T6 (also 1"). T6 are able to fit in the T8 ballasts, but they also give out 40% more light. The lower the number, the more efficient the tube. The number after the 'T' is the size of the tube. Other available lighting is Metal Halides (MH), these are useful for large or deep tanks but they are inefficient due to the heat they produce.

    Full-Spectrum (Tri-Phosphor) Lamps

    Widely regarded as the best light for growing aquarium plants is the full-spectrum lamp although no data has been provided to support this. This means that the light output peaks in three (regular T8s peak in two) colours giving a “fuller” light more likely to meet the plant’s photosynthesising requirements. Photosynthesis occurs most efficiently with peaks in the red, green and a bit of the blue parts of the spectrum. Plants are adaptable and will change their pigment distribution and content to adjust to the available spectrum. Most full-spectrum lamps will give a cool white light, ideal for both plants and for viewing and will have a high Colour Rendition Index (CRI) meaning that the illuminated objects will appear in their natural colour, these tubes are not produced for plants, but for the human eye, it is what looks best to you.

    Overhead Luminaires are a great way to add extra lighting, they clip on the glass and hang over the tank. Some models come with two switches so that is possible to have all the tubes running halfway through the lighting period to imitate a midday burst of sunlight. Luminaires are also more asthetically pleasing due to the fact that you cant see the rim of the hood.
    [​IMG]

    For nano's, there are some smaller versions such as the Arc Pod which are available in 9w and 11w.
    46248_Arcadia_Arc_Pod_1.jpg
    There are cheaper alternatives, such as these available off ebay which I have recently purchased and are so far good value for money.
    DSCF0005-1.jpg

    Another way to add extra lighting is to buy the tubes and fit them into the existing hood. The tubes usually come supplied with clips which screw on. Here is how i have done mine on my Fluval Elite 60:

    filter001.jpg
    DSC00256.jpg
    DSC00255.jpg

    COLOUR TEMPERATURE

    This is the colour of the tube’s output measured in degrees Kelvin (K). The 'best' colour temperature for plant growth replicates daylight at around noon on the Earth’s equator and is approx. 5500K to 6500K. This is a white light and is normally produced by full-spectrum lamps. There are other tri-phosphor lamps available which give varying colour temps ranging from 3000K to 10000K. The lower the colour temperature the redder the light, the higher the temperature the bluer. I have heard of and experienced success stories with a wide range of colour temperatures. I would recommend having a K between 5500k – 11 000k, but to be honest as long as there is enough light, then don’t worry to much about the Kelvin, The spectrum is far more important (Red, Green and a bit of Blue).

    LIGHT CONTROL UNITS (BALLASTS)

    These provide the power to the fluorescent tube(s). Two main types are sold - magnetic and electronic. Magnetic are less efficient as a lot of the power supplied is wasted in heat i.e. a 40W tube may use 100W total power (40W for the light, 60W wasted in heat). One advantage is that they are cheaper to purchase and are known to be very reliable (in particular the Arcadia ballasts). Electronic ballasts are a lot more efficient giving off virtually no heat; they are also a lot lighter (weight) but they are more expensive. Both types of units can power either single or two tubes. Magnetic ballast will start with a 'flicker' which means the tube last less time. This is why people suggest changing each year. Lamps on an electronic ballast will start after a half second delay with no flicker and therefore don't deteriorate so quickly. These can last 2 years+ before there is sufficient deterioration, thats they need changing.

    REFLECTORS

    Reflectors (also known as light-enhancers) are a simple way of increasing the light intensity and efficiency. All the light available is reflected toward the plants. It is the cheapest and easiest way of getting the most from your lighting. To retain maximum efficiency the reflectors and tubes must be cleaned regularly.

    LIGHTING DURATION (PHOTOPERIOD)

    Lighting should be on for 8-10hours a day, plants do not recognise photoperiods of less than 4 hours. Lighting can be switched on and off when you like, a ‘midday burst’ can be added when additional lighting is turned on for 2 hours to recreate the sun at its highest point. Some people also recommend having your lighting on for:- 5hr ON 2hr OFF 5hr ON – This is supposed to keep algae at bay and it is useful when using DIY CO2 or fermentation kits, this is called a ‘siesta’ period. I have tried using this technique and for me it didn’t work, if anything, it was damaging to the plants they will prefer 10hours straight. Plants are supposed to adapt to a small dark period whereas algae is supposedly not so adaptable - but it is!!. Recommended siesta periods can be from 1 hour to 3 hours with a minimum of 4 hours of lighting either side of the siesta. Try to stay away from this technique, i was just highlighting the meaning of it.

    Timers are a very effective and convenient method of controlling photoperiods. One can set the timer to switch off at a time most suitable to the viewer. I have my lights switch off just before i go to bed and i keep them on 8-10hours straight.
    When first setting up your aquarium, it is becoming more popular to run the light for 6hrs per day. This minimizes the chances of algae growth while the balance is still unstable in the tank.

    To summarise - If you wish to have a long-term successful heavily planted aquarium, full of lush growing plants then I would recommend having approximatley 1-1.5wpg. This will slow growth so the tank will have a longer period of time to mature.
    If you wish to have a short-term successful planted aquarium, then i would reccomend 2-2.5wpg of lighting. Going higher than 2.5wpg becomes difficult to create a balance, and there is a much higher chace of algae growth. However you MUST inject CO2 and fertilise regularly if these light levels are achieved. A balance must be kept between Lighitng, CO2 & Fertilisation to prevent algae blooms. More light requires more CO2 and nutrients (aim for a constant 25 to 30ppm of CO2).


    I hope this may help to answer some of your queries.

    Thanks for reading, Aaron
     
    nayr88 likes this.
  2. George Farmer

    George Farmer Founder Staff Member

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    Who uses these?
     
  3. aaronnorth

    aaronnorth Member

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    Not many people as a guess but that is what they are based on isnt it?
     
  4. SuperColey1

    SuperColey1 Member

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    I think shop fittings are still T12. The sort that are in offices and....shops. I'll bet some people use these when they are DIY(ing) their lights.

    Andy
     
  5. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

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    Chicago, USA
    Hi Aaron,
    Nice effort on the article. Lighting always causes grief and is often poorly understood. A couple of items you may want to consider though:

    There is a typo in your WPG calculation. You should correct it to read Total Wattage / Total US Gallons instead of the reverse. Your sample calculation actually shows 0.5 GPW instead of 2 WPG.

    I reckon it causes more confusion to use T12 as a reference bulb type since virtually no one uses this. It would have been better to use T5 as a reference and also to cross reference it to T8.

    There is a typo in the listed diameter of the T5 tube under "Types Of Lighting". T5 is 5/8 inch diameter not 1/8 inch. It might also be worthwhile to mention that the number afte the "T" indicates the diameter of the bulb in eighths of an inch.

    Although full spectrum bulbs may be regarded as "best" light no data has been produced demonstrating this. Plants are adaptable and will change their pigment distribution and content to adjust to the available spectrum. It is this "widely regarded as best" label that emboldens vendors to charge scandalous prices for their bulbs. CRI is also completely irrelavent since this only applies to what humans percieve, not what plants need.

    Additionally, very few if any aquatic plants ever see full spectrum midday sun, since they grow under the canopy shade and under murky waters in the rain forests of the world, thus rendering the value of Kelvin temperature or of full spectrum completely moot. In fact no bulb even comes close to the spectral distribution of the sun. Having a few peaks in a few narrow bands does not approximate the sun in any way shape or form. The term "Full Spectrum" is merely another marketing term used to suck people in. The Kelvin values of bulbs as well as the "best" term have only to do with what you like to see, not what the plant is capable of assimilating.

    Under the Lighting Duration section I reckon the siesta should be discouraged at every opportunity. Alage are THE single most adaptable plant species on the planet so the siesta idea is a complete illusion.

    Cheers,
     
  6. aaronnorth

    aaronnorth Member

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    Thanks Clive, i have added some bits of info, and about T6 aswell.

    I only just realised there wasnt a light guide on here! I was quite surprised really.
     
  7. johnny33

    johnny33 Newly Registered

    Messages:
    3
    I'm interested in fitting an Interpet compact T5 lights in a 80 cm planted aquarium.

    The aquarium comes with daylight fluorescent tube and I also wanted to fit another tube for my plants so I thought instead making more holes in the plastic hood I can put a T5 tube and take off the old tube.

    Whats best if I put the T5 for my plants and fishes - Interpet T5 High Power Compact Lighting - Daylight Plus T5 Power or the Beauty Light T5 Power.

    Thanks
    John
     
  8. aaronnorth

    aaronnorth Member

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    Hi,

    I use the daylight tube on my tank, it has a huge green & yellow spike so therefore it brings out the plants well in flesh, although for photography purposes you will notice that most of my tank shots look illuminous!! So i am considering buying the beauty which is more equal across green, red & blue parts of the spectrum and therefore it may be better for bringing out all colours (fish & plants)
    thanks.
     
  9. Dolly Sprint 16v

    Dolly Sprint 16v Member

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    Arron

    Lightanatsic article

    Regards
    paul

    N.B I have asked the forum "what would be optium light levels to achieve" and the replies i recieved skirted around the question rather than giving a definitive this has answer my question, THX.
     
  10. glenn

    glenn Member

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    Location:
    Leicestershire
    hi...nice lighting tutorial, good reading.

    im looking for new lighting atm. at present i have 2 30W t8 tubes over 180L so about 1.3 wpg-if i have followed your equation right.
    but im looking for 2-2.5 wpg.
    and i was wondering what you would recomend (my tank is 100cm long) halide lighting is an option but not preferable.
     
  11. aaronnorth

    aaronnorth Member

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    have you considered a luminaire? you can get a 2 x 54w T5 on ebay for around £100 or even cheaper if you keep your eyes open.
     
  12. davidcmadrid

    davidcmadrid Member

    Messages:
    115
    Hi,

    This is my first post and I am at the beginning of my hobby in a way. I have two tanks one with a pro co2 / measured ph ( stocked with fish ) and one with DIY CO2 ( appx 38ppm ) with no fish. The one with no fish is my experimental tank and is 70 liters.

    I am experimenting / learning light using this tank and dosing NPK and trace elements using EI, one week into the experiment and I have zero algae growth . Currently about 4 inches above the surface I have 1x 15W blue sky sera 12,000K light and am playing about with using lights outside the tank shining in through the glass. The light outside the tank is a 6K ( accurate as its part of my studio photo kit ) 100W focussed ( narrow spread ) light. I was thinking to get some rated philips eco bulbs and build my own array mixing up 7K bulbs with 2.5 K bulbs. I am assuming that as the light is going through the glass a lot of the UV below 300nm is being filtered out

    Does anybody see downside to using these rated flourescent eco bulbs for tanks and is there a reason that the lights are mounted above the tank as oppossed to being " fired " in from the sides ? What i am noting is that when I focus the light onto a particular plant its activity is increased somewhat visibly in terms of the amount of oxygen coming of it. Is it possible to " drive " plants too hard ?

    I am about to start experimenting with Java Moss and i believe in particular it favours light in the 2.5K range ?
     
  13. aaronnorth

    aaronnorth Member

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    Location:
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    hi & welcome :)

    Glass doesnt filter UV out, unless it has a coating (like sunglasses) which i doubt aquariums have,

    It doesnt make much of a difference where you place the lights, remember plants grow towards the strongest light source so having lights on the side will make the plants grow/ lean towards the side!

    Also i think it is just out of practicality, having lights above the tank, IMO, is much more aesthetically pleasing and takes less room.


    more light = faster growth.
    Having unlimited nutrients (EI) and 38ppm CO2 is the best way to get optimum growth out of plants, however, raising the light levels too far could result in you not being able to keep up with nutrient demands, and more organic waste is produced from the plants leading to a higher risk of algae.

    The kelvin of a tube doesnt make much difference to plant growth. I have grown plants succesfully from 2900K right up to 18 000k without any problems.

    Plants use red & blue waves in the spectrum, so a 2500k tube should contain a higher peak in the red waves, but overall, any tube even containing a small peak will be plentiful for plant growth

    Thanks
     
  14. davidcmadrid

    davidcmadrid Member

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    115
    Thank you for the answer :D My plan is to push light from the front one day and then the back. It is logical that the uptake may be greater so at the moment i am just watching for signs of poor growth ( i just spotted a few pinholes in a plant which i have tracked as a lack of magnesium ) Yes its not so pleasing to the eye but my thinking in the short term is that I just want to see what is possible and also multiply the plants as quickly as possible for the larger tanks in this test tank. Im also keen to see what i can make for about 50 euros instead of the asking prices for some of the kit in my lfs , they have seperated me from enough of my money for now and with DIY i get to keep the costs down a bit ( the eco bulbs also have low consumption being rated energy a ).
     
  15. aaronnorth

    aaronnorth Member

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    pinholes are usually a sign of a potassium defficiency, with magnesium usually being yelow & brittle leaves.
     
  16. lljdma06

    lljdma06 Member

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    Location:
    Miami, FL
    I do not totally agree with this statement. You do not need a minimum of 2WPG to get a lush tank of healthy growing plants. If you pick your plants correctly, you can probably do well with 1WPG or a little less if using T5s. This, of course, depends on the tank size. The smaller tanks would need significantly more, and the very large ones less.

    But you know you're one of my favorite people anyway. :)

    lljdma06
     
  17. aaronnorth

    aaronnorth Member

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    lol, i actually disagree with it myself 8) :lol: it was a long time since i wrote it, i learn something new everyday lol.
    I'll change it.

    Thanks
     
    Dogman Mike likes this.
  18. lljdma06

    lljdma06 Member

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    Location:
    Miami, FL
    :lol: :lol: :lol: That's funny.

    Hey, I'm getting my finances in order and I'm going to see about that 36g in my Florida Room. I'm going to try an experiment. Which do you think will be better? 30W of T8 or 28W of T5. I'm leaning towards the T5s. It is technically less wattage, but t5s have more output. This will be thel lowest light level I have ever gone. Let's really bend the rules, shall we? ;)
     
  19. aaronnorth

    aaronnorth Member

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    Oooo! how about going for HC, some alternathera and Rotala macranda. See how well they do :D
     
  20. lljdma06

    lljdma06 Member

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    Location:
    Miami, FL
    I did the A. reineckii with 1.4, so I'm sure it would be alright. It's a deep tank, 21", so I doubt HC would take hold, and I'm not planting individual plantlets in a 21" corner bowfront. My hands would fall off. R. macrandra prefers soft water, and that would just be cruel to put it in Miami water. Right now, I have 65W of Compact Fluorescent, so about 1.8WPG. I just cannot justify that amount of lighting for what will really just end up being anubias, crypts, bolbitis, swords, and other low-light plants. There's too much light in it now and not nearly enough plants. I'd rather do an overhall and change everything. I want very slow growth and very low-maintenance. I'm guessing the stocking will change too. I'm just mulling things over right now.
     

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