LED lighting for planted aquarium

[Ice222]

My dad has a friend whose company sells LED lights, mostly for signs and such, but I heard that they also have LEDs for plants. Aquarium plants are still plants, so logically I assume they could work for aquariums too. So I did a bit of hunting online for info on LEDs for plants, and found out that the optimal wavelength for plant growth is 400-520nm for the blue and 610-720nm for the reds. I also read that blue light promotes growth while red light promotes flowering, but I had a hard time finding what the overall ratio of red to blue LEDs should be for plants, let alone for aquarium plants specifically. I did find that both the reds and blues are needed even if you don't particularly want flowers though. The closest info I could find on red-blue LED ratio is from http://www.earthled.com/growled-led-grow-lights.html whose plant LEDs sit at around 64-77% red lights.

Yea I know you can buy ready made LED lights for aquariums, but most are just moonlights, and true aquarium plant lights they're very expensive and hard to find in NZ, not to mention that I'm kinda keen to experiment with a little DIY . The advantages I see with LEDs is customisability, low power usage, directional light, and it sounds pretty easy to control LEDs to set different timings for them. Not to mention that they have very little heat output compared to most other bulbs so a fan might not be needed, and a long lifespan, so if this works out it could really be awesome.

Don't know if I'll ever actually make this, since I still need to figure out the cost of the LEDs and still have several technical things I need to work out first, but I thought I'd post here in case if anyone knew the answers, or if anyone is keen to try making DIY LED aquarium lights too.

What I still need to find out:

1. The best way to make the light more easy on the eyes for viewing. Whether to add white LEDs or add some green LEDs. Since with light, Blue+Red+Green=White, it could work in theory, although trying to find the specific wavelength of green to get a good shade of white would probably be more hassle than anything.

2. The ratio of red-blue-white or red-blue-green to have for the setup.

3. The right output of LEDs to use. Apparently LED output isn't best measured by Watts, so I'm not sure how to compare it to the output of fluorescent and MH lighting equivalent, as such 'Watts per gallons' and similar rules don't really apply and so it's a little hard know how much light is too much or too little light.

Cheers to anyone who actually read this lengthy post :lol:.

[HaNs]

You need to look at the lumen output of the LED's. Its not hard to do, you just need the time

http://www.ultimatereef.net/forums/show ... p?t=327073

http://fishkeepers.co.nz/forums/viewtop ... =14&t=2220

[Ira]

Just don't compare the lumens/watt for your led lighting fixture to good fluoros then look at the price. Even worse compare them to a metal halide. The original Solaris LED fixtures which are a couple years old now were getting somewhere around 20 lumens/watt compared to metal halides at about 80 while cost 4-5 times the price. So about 1/16th the bang for the buck. LEDs have improved a lot in the last 2-3 years, but they still suck for bang for the buck.

[Ice222]

Thanks for the links, I'll check them out in greater detail once I get a chance and I'm gonna check out what the prices are like for decent light output. I still need to get a job and save up money for a bigger tank setup before I do anything with the lighting anyway, Prices of LEDS have been dropping the last few years anyway, so who knows it might actually be pretty affordable soon .

[phoenix44]

LED's for aquaria are not cheap. :lol:

T5 HO's are a better option.

[breakaway]

I always get excited every few months and look into LED. But once I price up the ballast, the LEDs, the heatsinks, it's often way more dear than getting an off the shelf unit.

This way you also save the hassle of having to build everything.

[Ice222]

http://www.trademe.co.nz/Building-renov ... 772516.htm

Would something like that work if I can get the right colour temperature?

[Ira]

http://www.trademe.co.nz/Building-renovation/Electrical-lighting/Lights/Inset-lights/auction-300772516.htm

Would something like that work if I can get the right colour temperature?

Yeah, if you can find the right color temp it should work ok. But then you're still talking similar lumens per watt as an average T8 fluoro. That one's 54 watts, T8s are in the 50-80 range. So you'd need 8 of them to match the light output of a single 4 foot fluoro tube with a good reflector. At least 16 or so for a 200l 4 foot tank. So that's $640 before fittings to match a $50 4 ft dual fluoro. Now, the need for a good reflector for the fluoro bumps it back towards the leds a little...But not much.

[Ice222]

The ones I can get are 100lm per watt, with 3 LED or 7 LED varieties, in a similar style to the one I linked in terms of appearance. I can get the 3 LED variety for <$25nz and 7LED for <$40NZ each. The cost for a fluro decreases as you go up in length, whereas LEDs have more or less a flat rate of increase based the number of bulbs you so I don't know about bigger tanks, but for smaller tanks I think LED is viable, the options in NZ are pretty limited but getting them from overseas means I have more options.

Say for a 2 foot tank an AL-20 with reflector is 24w, assuming 100lm/w thats 2400lm for $90 not inc shipping. Now 3 700lm LEDs 'bulb' each plus 1 300lm LED 'bulb' creates the equivalent of 2400lm for $145 total. That's $55 difference but you don't need to change them every year and you basically get the benefits of a MH with the focused light, the 'shimmer effect' as well as being able to turn them on and off with a dimmer rather than that fluro flicker. Not to mention that LEDs can be used for odd length tanks unlike fluros which could be too short or overhang on tanks that aren't sized at 1,2,3, or 4 foot. I'm guessing just the 3 7watt bulbs would work for a 2 foot, as long as the most demanding plants are in the well lit areas.

Reading from http://www.americanaquariumproducts.com ... hting.html I seems to suggests lower fluros have a lower lm/w output than the 100lm/w I based off of wiki any way and mention something about improved focused Lumens of LEDs making a significant difference in lumen output compared to florescent tubes.

[ledgrowlightau]

Maybe you can visit: www.ledgrowlight-aquarium.com.au

hope can help you!