Will switching to reef LED aquarium lights save money?

reef led aquarium light

reef LED aquarium light by SMercury98

I found myself asking the question: “Will switching to reef LED aquarium lights save money?” a lot lately–mostly because I’m overdue to change out my light bulbs.

So now that it is time to fork over the ~$110 to replace my lights (to purchase a new metal halide lamp and 2 power compact lamps), the questions I have been asking myself are:

  • Am I throwing money away by replacing my current bulbs?
  • Will switching to reef LED aquarium lights save money in the long run?
  • How long do I have to wait to save that money?

Will switching to reef LED aquarium lights save money?

In order to figure this out, I first had to calculate how much it costs to run my lights currently. As best I can figure, there are two dominant costs in running my lights today:

  • Cost to replace the bulbs annually
  • Cost of electricity to run the lights

The cost to replace the bulbs is fairly easy to figure out. A replacement metal halide bulb costs about $50 and power compact bulbs cost about $30 each, for an estimated total of $110 in my case. This number will vary for you based on the type of bulbs you need.

The cost of electricity to run the lights was a bit more complicated–first of all because you need a degree in forensic accounting to interpret my electric bill. Do yourself a favor and grab your utility bill to perform this calculation OR just trust that your electricity is similar to mine. What you DON’T want to do is just do a google search to find out how much you spend. When I did, what I found was the ‘cost to compare’ quote–which was only 1 of the various costs charged by my electric company.

For all these calculations, I created two easy-to-use spreadsheets that you can access/download for free. I posted them to Google docs. You can access them by clicking on either the text link or images below. Part of the beauty of saving to the cloud is that it’s really easy to let anyone and everyone have access to it. Just try to have good etiquette there and remember Google’s motto: don’t be evil :).

Reef LED calculator on Google Docs

reef LED aquarium light calculator

Download this tool for free

Cost of electricity calculator on Google Docs

cost of electricity calculator

Download this spreadsheet for free

Once I figured out how much I was paying per kilowatt hour ($0.15 per kwh at the time of this post), I could figure out how much I spend on electricity as follows:

hours per day lights are on x’s watts x’s cost per kwh x’s 0.365

which in my case meant:

14 x 305 x $0.15 x 0.365 =  $233.78

Combined, when you look at the cost for electricity and the cost to replace bulbs every year, I figured I’m spending about $343.78 each year to run my current lights–which is a lot more than I wanted to think.

To figure out the cost to run your new reef LED aquarium lights, you do the same math–but with the lower figure for the watts, based on what the new lights consume. It seems like 130 watts is a pretty common power rating for LED lights:

14 x 130 x $0.15 x 0.365 = $99.65

So the difference between those figures is the estimated amount of money I will save by running reef LED aquarium lights instead of my existing lights (assuming I would have changed my light bulbs every year as estimated).

$233.78 – $99.65 = $134.13

So if I were to switch my metal halide and power compact aquarium lights to reef LED today (instead of replacing and running my existing lights), I would save $134.13 each and every year.

But that isn’t just free money falling from the sky–because I already have a light fixture and ballast for my lights, I have to consider the cost of purchasing the new reef LED light fixture. I was surprised to see the wide range of costs out there on the market. First generation LED light fixtures can be purchased on Ebay or Amazon for $100-$150.
More advanced (and/or more recognized brand name) reef LED light fixtures are available for $300-$650.

So if I will save $134.13 each year, that pays for a $400 fixture in 3 years  ($400 divided by $141.80) or a $600 fixture in 4.5 years.

That seems like a decent payback period, considering that LEDs are claimed to last 50,000 years (which is roughly 10 years at 14 hours each day). To take the math one step further, if my reef LED lights do last 10 years, they will save me $818-$1018 over their useful life, over and above the cost of buying the reef LED aquarium light fixture. That seems like a compelling reason to switch.

From a financial perspective then, the decision comes down to whether or not there is risk in the lights burning out or otherwise breaking before the payback period.

Well, that’s the math. Hope walking through it helps you do your own assessment about whether or not switching to reef LED aquarium lights will save money for you. If you want to do your own calculations, you can use the spreadsheet I put together. I made it available on my Google Drive.

If you use the spreadsheet, please consider coming back to leave a comment here and post how your analysis came out, either for or against the purchase. I think others would benefit from understanding your perspective too.

Written by Albert B. Ulrich III. Follow me on Google + and Twitter

Some of the images above contain affiliate links to products available on Amazon.com. What that means is that Amazon will pay a small fee (at no additional cost to you) to support this website if you purchase anything from them as a result of clicking on one of those links.


  1. I think a pretty good case for the economy of LEDs can be made, especially if you are just starting out., but thanks for the detailed analysis.

    My concern is that LEDS are a much different kind of light. Being a beginner, I wonder if are they are good a light for a reef tank as T5s or Metal Halide for maintaining a healthy tank overtime. I have read / heard a lot of conflicting information about, more definitive resources seem to be lacking. The consensus at my local fish stores is that T5 are superior for the health of tank , especially longer term than LEDs. (My understanding is that for proper coral grow Metal Halide really can’t be beat, but their expense and downsides (heat, cost) make them more appropriate for ‘hard core’ applications. One argument I heard against LEDs is their lack of UV emissions which I was told coral need to have long term. Any comments appreciated! Thanks!

    1. Author

      Hi Sam,

      Thank you for stopping by the site here and for leaving a comment. I think the answer to your question is…it depends (how often do you hear that in this hobby?) Here is my take on it. I think any of the technologies you list are appropriate to grow corals. Each one has pros and cons. One of the toughest things in this hobby is that there is no one-size fits all. The technologies are all different and the animals we keep in our tanks come from different parts of different oceans around the world. What’s ‘best’ for one animal is not always the same for every other animal. I suspect you may agree with that theory subjectively, but check out this article comparing coral growth LED and LEP lights (two different lights.) The conclusion from the study was that coral growth was species dependent (not dependent on the type of light.) Another article, by Sanjay Joshi, takes a deep dive into comparing the power input and power output of the major lighting types and shows, among other things, the PAR difference across the lights at 2 distances.

      Some higher end LED fixtures do include UV. Unfortunately, nothing comes to mind as far as empirical proof of the effects of UV light, the different technologies and the long-term health of corals. It would be an interesting study.

      Check out those articles and let me know what you think. I hope you find them to be helpful. They are technical, but supported by data–and that’s what I try to rely on when opinions seem to conflict (as you indicate). Data aren’t perfect either, but they are a good place to start.

Leave a Comment