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Topic: My Arduino Aquarium Controller (Read 73879 times) previous topic - next topic


RGB LED's are really not that expensive.  $0.99 each is really not that bad.  http://www.mpja.com/prodinfo.asp?number=17137+OP


I don't mind about the cost. I'm wondering about the color. Wondering if anyone has the RGB combo to use.

I'll probably order some today and let you know what I come up with.


This is terrific. I keep Vivariums at home (Partial water and partial planted area terrariums, usually for maintaining a population of tree frogs, salamanders or amphibians) and I would love to build an arduino-based system for maintaining moisture and temperature. Right now I have an ultrasonic mister and lights on a timer, but it's crude, and it would be great to have some fans kick on over a certain temp or foggers start below a certain humidity.


If you're really interested in learning about lighting I'd highly recommend this site:



Interesting. I found an article about LED lighting where they break down what colors show up. It looks like 45% blue, 20% red, and 35% green.

I'll be doing some more reading on this site... lots of good info.

Thanks for the link, it's helped a lot.


Thanks for all the help everyone. I've ordered a bunch of stuff: ph sensor, temp, float, rgb leds etc.

A big thanks to jener8tionx... the links on your site saved me a bunch on the LCD and the ph sensor as well as show me an outline on what I should get.

I've gotten some plexi which I'm preparing for the LED array (100 rgb, 50 on each half). My thoughts were to use 3 pwm outputs to drive some mosfets (I have some IRF540's 100V 22A, more than is needed I know). Does anyone see any problems or have suggestions to that? The LED's will probably be hooked 2 in a series X 25 in parallel.

I'm going to be documenting the project on my site with pics and videos, links to come when I've actually started.


Since LED's are diodes, each with a different specific forward voltage, will hooking them in parallel work? I thought the lowest forward voltage diode would get all the current and expire horribly. That's why I was considering doing my lighting direct from the mains. I'd have a nice high voltage and connect them in series.


Thanks for the comments everybody!


Aug 06, 2009, 01:13 am Last Edit: Aug 06, 2009, 01:14 am by Bricoducat Reason: 1
I have been thinking about lighting, but for fresh water, the problem I face is which wavelentgh to use:
chlorophyl a has 2 absorption peaks 430nm and 670nm
that's the wawelentgh of the led you should use for max efficiency.
chlorophyl b 475nm 630nm
The biology question is which is optimum for your tank (guess it depends on your plant)
the source for high power led I found is http://www.roithner-laser.at/
quite expensive but getting cheaper, still on a watt per ? tubes still rule.
Led advantage is ease of control, getting THE right wavelentgh for growth of you plant and not algae (if only I was sure of which one it should be for my tank)...


The RGB led's I've ordered have a blue wavelength of 460nm and RG of about 525 and 625nm. I'll have to work everything out to get all 3 working well. I think I'll go for 600ish nm as that seems to be a good all around bet.

Lots of stuff to figure out still....


I was interested in LED's because of the low heat generation. With some of the lighting you need to buy an expensive refrigeration unit to keep your tank cool. If I could dodge that cost (and lower AC bills) I thought it was worthwhile to consider.

You might also read the papers on water movement in the link I posted earlier. I would think it would apply to freshwater too. If the plants can't get to the elements they need for photosynthesis then all the light in the world won't help them.


Awesome thread. I'm considering a similar project.

Anyone interested in LED for aquariums should check out the DIY forum on Reef Central, and the LED threads on nanoreefs.com. In both of these forums, a lot of the groundwork is laid out. It's important to get the right LEDs in terms of color spectrum, but also efficiency. You're going to want the highest-output bins you can find, of a high-output LED like the Cree XR-E or Luxeon Rebel.


Been on nanoreef.com for quite a long time. Some really good info there. I'm not going to go with the high output LED's because I thought it'd be cool if I could show off to my friends by having the lights change color (not all the time).

After looking at all the links everyone's posted I feel pretty confident that the LED's I have ordered will work pretty good. The red provides 460nm and green/blue provide 600/615nm. That's pretty close to the optimum values.

All I need to get started is the parts! Waiting for them to arrive sucks so much.


What did you use for a pH sensor? I checked your Wiki link but didnt see it listed.


Here you go:


We are still working out details for a better way of doing pH though.

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