How to choose LEDs for an aquarium

[Cliff]

I thought I would post these simple guidelines, or rules of thumb, that I have learned when purchasing LED lighting for both my fresh water and marine aquariums. This is not and all inclusive set of instructions, just something simple to get you started if you have no experience with LED lighting. Most people do not pay attention to the angle of the lenses used or do not understand how different the wattage can be with a LED diode (as compared to a T5 or T8 bulb) and they end up with a fixture that really will not meet their long term needs.

As many people are looking into getting LEDs I thought I might as well post this

- For tanks that are 36 to 48 inches long and 12 to 24 inches tall, I would suggest a fixture that is about 6 to 8 inches wide (or even a little wider)
- For a 48 inch long fixture you should have around 30 to 40 1 watt LEDs, either Cree or Apollo manufactured LED diodes. For a 36 inched tank, about 25 to 30 1 LED just as mentioned. This would give you the options for easy to keep and some of the moderately depending plants. Get a fixture with about 20% more LEDs if you think (or are planning) that want more demanding plants in the future or corals for a marine set-up.
-If you are putting this fixture on a freshwater set-up, then choose LEDs with a color temp of less than 7,000K.
-If you are putting this fixture on a marine tank, then choose LEDs with a color temp of higher than 12,000K, 18,000 to 20,000K is best.
- For a fresh water set-up you can add a few red or Fugi pink colored LEDs if you want to help the colors in your tank "pop"
-For a marine set-up you can add a few Fugi pink or actinic LEDs you want to help the colors in your tank "pop". You can also have a 50/50 mixture of 12,000 to 18,000K white and 22,000K or higher blue LEDs and still support coral growth (most corals) while limiting algae.
- add a controller to adjust the intensity of the light if you want. Many different manufactures make the LED controllers differently with a lot of different options. You should research this carefully so you know what you can and cannot control.
- For lenses, I would suggest a mixture of about 50% of the lenses around 40 to 60 degrees, the rest around 60 to 80 degrees. This will determine how much light intensity will be reaching the bottom of the tank and is just as important, if not more important, than the wattage of the LEDs themselves. The below simple diagram (not to scale) can help you better understand what I am talking about

[sheamurai]

great little primer, Cliff.

[DeboraBremner]

Helpful info Cliff...thanks!

[Taurus]

Very helpful Cliff, thanks.

[Triton]

Thanks cliff. I want to build my own but have seen the costs can vary from $100-500 lol. Trying to determine if it would eventually save enough in bulbs and electricity

[jeffs99dime]

Nice, informative write up Cliff. This should be made a sticky.

[FrozenTundra]

good information.

[Cliff]

thanks guys

Thanks cliff. I want to build my own but have seen the costs can vary from $100-500 lol. Trying to determine if it would eventually save enough in bulbs and electricity

I have read a lot of info from others who claim that you break even at around 3 to 5 years of use (depending on exact details) and save money money after that point. I don't know how true at is, but it does seam to make sense to me.

[Triton]

Yea right now I'm running 108w on my 75, but want a better more efficient lighting design