Led Lighting For A Freshwater Planted Tank

[Fishyworld]

Hi,
 
I have a 12gallon tank, dimensions 54cm wide 35.5cm tall and 25cm deep. I have danions and I will be adding Corys. The plants I have are x1 Java fern, x1 Penny wart, x1 Green rush and x2 Chainsword,
I would really like the plants to flourish.
 
The light I have is a piece of LED strip suspended 13cm above the tank. The information on the strip is bellow.
 
Length: 55cm
4.8w per a meter
660lumens per a meter
colour temperature 6500k
 
Is that a strong enough light output for my plants (I can add another piece of strip with the same specs)?
Also is the light to strong for my fish because all but one of them now hide while the light is on?
 
 

 

[Lizzard111]

It's very difficult to tell how much light you should have. I bought LED's from american company which stated that 1Wof LED's is equivalent to 1W of light bulb.
I personally don't agree with it as I replaced 39W with 2x 14W and I have much more light. Also lumens are used as a guide only because in LED's it's difficult to tell due to different technology of led's and light spreading. LED's are focused light so you can for instance have 12W in one inch, or you could have LED's with cover which spread evenly on whole aquarium and get 12W also.
 
You can check where the light goes and you'll know which plant will benefit from it,if it goes mainly at one point then move plant there. Fish shouldn't be scared of light,might not get used to this "different lights" if you have dark here and light here but they should be ok.Only those fish which like to hide and are calm e.g. Glass catfish tend to hide or look for shadowed place.
 
I don't know about Danios but they don't seams shy so it shouldn't bother them,as for plants you can wait and see if plants from the back are growing faster.

 

[Fishyworld]

Thanks Lizzard111 =)
 
My fish have stopped hiding so I think it was the initial shock of going from dark to light that made them hide.
 I have since read that an aquarium needs around 0.5watts of light per a Litre. My LEDs are actually 390lumens not 660lumens like I originally thought.
390lumens roughly equal just under 40watts so going with 0.5watts per a Litre the light out put of my LEDS should be enough I think. As for the spread of light the LEDs I bought, have a beam angle of 120 so they give a nice even light across my aquarium, however the brightest light is directly underneath them, so that is were I have situated my plants.

 

[DrRob]

Sadly ignore all wattage stats for aquarium needs, unless it's been calculated by someone sensible for the specific light that you have, even then it'll depend on a lot of other parameters.
 
Lumens are slightly better, but tell you the visible brightness to a human, not to a plant. Some great plant growth bulbs don't look that bright to us, the classic example of this is the red/blue grow lights that plants thrive under and don't look all that much to us.
 
Overall LED's are still quite variable technology, the high quality ones turn out huge amounts of light per watt, the cheap ones....don't.
 
Wide beam angles avoid the spotlight effect, but also spread the light over a wider area, reducing the intensity at the substrate, Narrow beam angles punch light to the depths far better. My favourite rig I've seen has some wide angles running across the middle with a selection of narrow beams at the front to light the carpet areas. He took months building it though and has no intention of doing it again.

 

[Lizzard111]

As DrRob mentioned lumens aren't good here. Best indication of light is price in my opinion. I bought in January 2012 Aquarey Gro Beam 500 (now they have better ones 600) and I'm very pleased with it. Website changed but you could see comparison with different lights and also effects for plants (should be loads on you tube).
Here's the link for those LED's http/www.aquarayusa.com/grobeam.html
The only disadvantage I would say it's heavy (I have it mounted to my tank cover and need to lift it up all the time) and also price is really high. I could go for cheap ones but again Aquaray as only company gives 1 extra year of guarantee (I'm not sure but I think it's 2 years) but still ppl on forum say it should work for 5 years.
 
So if they give long guarantee you shouldn't be worry about quality and as it goes for light (as mentioned by DrRob) for better light spread and general light you should look for as much wide angles as possible (just don't overreact on it, you don't need light on wall and top of the tank). And for carpet light you need focused light so small angle. Also you can notice that GroBeam and other companies should have different LED's for small tanks and high tanks (over 50cm tall etc.) which is angle vs light focus.
 
I have one LED strip on back and I'm really pleased about it (had broken power supply when bought but they replaced it without problems) and plants look 100% better,I wish I could have one on front but it's too wide so I wouldn't put my hand into tank (need to clean it somehow,it's 300L after all). If you watch tank every day like me it's difficult to see light going down slowly every week if you have standard light,with LED's they always give same light although when calculating life spam of light bulb and LED light bulb will always be cheaper.
 
2 light bulbs per year £20 which is £100 after 5 years
If my LED's will last 5 years we'll get £180 plus power supply $20  1 year guarantee (not sure how much it's in pounds),also note they're not as common so replacement isn't like getting it from shop on same day
Advantage I see is more light where limited space is and no hassle with changing light every few months.
 
If I would go back in time I would still buy it