Mr. Saltwater Tank

Terrible Advice Tuesdays (Special Edition): The Cheapest Way To Light Your Aquarium In An Emergency

Terrible Advice Tuesdays: Metal Halide lights can be powered by combining Diet Coke and Mentos in a closed container – in an emergency and ONLY in an emergency.

The rest of the story: One of my high-end aquarium installer friends *cough* Ben J. (I’m leaving off his last name to protect his identity) swears by this method. He claims to have several fully grown out reef tanks in multi-million dollar homes and whenever there is a power outage in his area, he simply delivers 2 Litre bottles of the fizzy soda and a 12-pack of the fresh breath mints to his client’s houses.

Ben doesn’t know it, but I secretly recorded a conversation between him and I and here’s the gist of what he says,

“Dude, this isn’t some ‘DIY’ project. Using Diet Coke and Mentos is serious business. I personally increased my business liability insurance because if the reaction goes wrong, high dollar wood floors get ruined. Not like just like, ‘Ill resurface it’ ruined, I mean totally ruined. All you have to do it plug the power plug from the light into the 2L bottle of Diet Coke. Make sure you don’t plug in the halide ballast to the bottle because if you do that, s–t will go really bad…fast.  Just plug the light directly into ballast. Then dump in the whole 12 rolls of Mentos and stand back. Within seconds the halide light will flicker on and you will look like a hero. Why you haven’t done a Mr. Saltwater Tank TV episode on this, I’ll never know.”

While Ben has had some really cutting edge ideas in the saltwater tank world, including cutting corals to create smaller “fragments” that then grow into larger pieces of coral, that then can be sold to make real money, the idea of using Diet Coke and Mentos to power Metal Halide lights in ludicrous. I can maybe, maybe see powering a LED fixture with Diet Coke and Mentos, but not halide lights. Halide lights require using full-strength Coke as there isn’t enough Standard Reduction Potential in Diet Coke to provide the electrons needed for the lights.

Nice try Ben, but Diet drinks just don’t work in this case.

note: Yes, this is an April’s fools post and yes, please don’t try it at home!








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Comments for this article (19)

  • Joe says:

    I tend to follow the advice before finishing the article. This one burned me. I need a new floor. Thanks!

    April fools back at you.

  • andrew says:

    Good one!!!!!! I was going to try this but could not find a left hand wrench or water hammer

  • Antoine says:

    I only have 9 months in the hobby. Reading this article I’m like WTF. Who does this! Happy April fools.

  • Michael Horton says:

    Does it work with Diet Pepsi (for LEDs) and Pepsi (for halides) in a pinch, or only Coca Cola products? I’ve heard that Red Bull can lead to power surges.

  • Tony says:

    What? Diet Coke and Mentos? I thought we were supposed to plug the lights into a bottle of ACROPOWER! 🙂 (Not sure if Julian Sprung is going to like my comment…LOL)

  • David Carwile says:

    So Virginia Tech made a battery that runs off Maltodextrin. Maltodextrin and sucralose are common sweeteners used in diet products. So while this will make power, I wouldn’t do it. By the way the VT battery could power your cell phone 10x better than lithium ions. More info on the VT battery:

    – Hokie 🙂

  • Shane says:

    Where exactly would one insert a plug in a bottle? Im no engineer but liquids and electric sockets aren’t really the best of friends

  • Carl says:

    I knew it was a joke. I just keep a basket of potatoes on hand at all times. They are a lot easier to plug into.

    I live in a place that experiences multi-hour power outages 3-4 times a year. I have gotten by on the vortech batteries. But I finally broke down and bought a natural gas powered home generator. We had our first outage about two weeks ago. The generator performed perfectly and automatically. The best thing was the piece of mind that I had that my tanks were unaffected with light, temperature and flow unaffected. Another side benefit was my family loved it as well.

    Mark, you might consider an in depth video on home generators.

  • Andy Nelson says:

    I had a feeling on this one Mark…. I mean plug it in where? Lol besides your wat to nice to throw your buddy under the bus!!! Cough cough!!!

  • Carl…the potato idea is brilliant! Please put together a working prototype and send it my way!

  • Keith says:

    I’ve seen this method of generating power mentioned before by Sloof Lirpa (a Mount Everest guide from Nepal). They use it in emergencies at Mount Everest base camp.

  • Carl says:

    Just follow this lady’s instructions on the potatoes. And, sorry you will have to by your own. I am a reefer and have no extra money to buy you potatoes.

  • David says:

    Mark, your buddy forgot to mention the most important ingredient, after the diet soda. You need to add a couple drops of halogen headlight fluid to the soda before dropping in the Mentos.

  • Carl says:

    Halogen headlight fluid would work great. I keep lot’s on hand to clean my filter socks with because it’s inert.

  • DeeFromBrooklyn says:

    I totally thought you were insane for a minute. Luckily I read through to the end because I could imagine this working

  • Lyle says:

    Mark you are a FRIGGIN no nothing IDIOT!

  • Lyle says:


  • CY says:


  • Cristian Albu says:

    I just use a lemon… an idea I got from my grade 6 science class, much more reliable.

    Good one though!!

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