Move over, potato batteries: DIY microbial fuel cells are here to stay! A microbial fuel cell (MFC) is a device that uses bacteria in an anaerobic (oxygen-poor) environment to convert chemical energy into electricity. [drdan152] posted steps on how to make a soil-based MFC with a neat twist: it’s also a fishbowl for a betta fish.
[drdan152] used soil from the wetlands, referred to as “muck.” This nutrient-rich soil provided a hearty supply of bacteria, especially Geobacter species, known for their uncanny ability to transport electrons outside their cells using bacterial nanowires. The proton exchange membrane (PEM) was made up of salt, water, and agar. After some initial runs, [drdan152] determined that flat char cloth made the best anode, while red copper wire served as the cathode. Assembling the MFC was as simple as surrounding the anode with a thick layer of muck on all sides, adding the PEM on top, followed by water. The cathode was situated halfway out of the water.
After a couple of days, the voltage increased in proportion to the amount of bacteria growing on the anode. The betta fish can happily live in this habitat for a short period of time(it still has to be fed, of course), and the bacteria certainly won’t mind – the fish’s excrement provides an additional food supply. As a bonus, the water is kept clean. However, like any aquarium, the water will need to be changed periodically
as carbon dioxide byproduct accumulates from the fish’s respiration and the MFC (high carbon dioxide levels = dead betta fish).
The MFC generates 725 mV. [drdan152] is not satisfied with that number, and is testing out charge pump circuits to generate as much as 3V. We are looking forward to seeing the results.
We also wonder if a small aquatic plant could help make it a more self-sustaining environment for the fish. In the meantime, [drdan152] is encouraging others to try larger-scale versions of this MFC. Perhaps MFC-powered carnivorous robots doubling as mobile aquariums are in our near future.
[Brian] has a fairly large 400 liter aquarium and loves the fish that call it home. Unfortunately, sometimes life gets in the way of keeping those fish fed on a regular basis. There are automatic fish feeders out there on the market and [Brian] gave one a try. Although it worked, it dropped one huge clump of food in at a time (rather than sprinkling it in), the food hopper held a very small amount of food and the unit drained a new set of batteries in less than a week. Fifty euros were spent on purchasing that auto feeder and in the end it wasn’t any more convenient than just feeding the fish.
Faced with a tough decision on whether or not to buy another product he may not be happy with, [Brian] decided to make his own automatic fish feeder system out of parts anyone can find lying around the house. The main housing is a small Tupperware bin, inside of which 3 pieces of plastic were glued together to make a v-shaped hopper. The fish food is loaded into the hopper and as it falls to the bottom it meets a reverse-spinning drill bit that acts like an auger, pushing the food out of the container. The drill bit is powered by a small stepper motor connected to the drill bit by an improvised coupling made from a silicone sealant cap!
The control system is an Arduino and a stepper motor driver chip. Through trial and error [Brian] figured out that 100,000 half steps of the motor dumped a good amount of food into the tank. The drill bit delivery method even sprinkles the food nicely for total fish enjoyment. To keep the food flowing at regular intervals, an AC timer unit controls how often the Arduino is powered on and subsequently feeds the fish.
Continue reading “DIY Auto Fish Feeder Feeds Fish Automatically”
Over the course of a few weeks, [Adam] trained his betta fish, [Jose], to jump out of the water to snatch food off his finger. An impressive display for a fish, but being able to train his small aquatic friend got [Adam] thinking. What’s stopping [Jose] from interacting his environment even more? The abovemarine was born.
The abovemarine is a robotic platform specifically built for [Jose]‘s aquarium. Below, three omni wheels drive the entire aquarium in any direction. A computer running OpenCV, a webcam, and a few motors directs the abovemarine in whatever direction [Jose] wants to go. Yes, it’s a vehicle for a fish, and that’s awesome.
[Adam] put a lot of work into the creation of the abovemarine, and was eventually able to teach [Jose] how to control his new home. In the videos below, you can see [Jose] roaming the studio and rolling towards the prospect of food.
Because [Jose] is a Siamese fighting fish and extremely territorial when he sees other males of his species, this brings up the idea of a version of Battlebots with several abovemarines. They’re in different tanks, so we don’t know what PETA would think of that, but we do expect it to show up in the Hackaday tip line eventually.
Continue reading “The Abovemarine”
Whether you want to keep your fish happy or just need a good light show, this aquarium light fits the bill. It is the second iteration, but [William] calls it v1. That’s because v0 — which used a few loops of LED strips — never really met his requirements.
This build uses just six LEDs, each a 30 Watt RGB monster! To source about 350 mA for each, and to control brightness with 18-channels of pulse width modulation, he had to plan very carefully. This meant a proper aluminum project box and a beefy, fan-cooled power supply.
The driver board is his own design, and he etched a huge board to hold all of the components. Everything is driven by an Arduino Mega, which has 16 hardware PWM channels; two short of what he needed. Because of this he had to spend a bit of time figuring out how best to bit-bang the signals. But he’s putting them to good use, with fish-pleasing modes like “sunset” or the “passing rainbow” pattern which is shown in the image above.
If you need something a little less traditional why not house your fish in a computer case, complete with LED marquee for displaying data.
People have been converting their old Power Macs and Mac G5s into fish tanks for a few years now, but [Hayden's] Internet-enabled tank is probably the most awesome ever crammed into an aquarium along with the water and the fish—and we’ve seen some fascinating builds this summer. After gutting the G5 and covering the basic acrylic work, [Hayden] started piling on the electronics: a webcam, timed LED lighting, an LCD for status readouts, filter and bubble control via a servo, an ultrasonic sensor to measure water levels, thermometer, scrolling matrix display, an automatic feeding mechanism, and more. He even snuck in the G5′s old mainboard solely for a cool backdrop.
The build uses both a Raspberry Pi and an Arduino Mega, which sit underneath the tank at the base. The Pi provides a web interface written in PHP and jQuery, which presents you with the tank’s status and allows changes to some settings. Nearly every component received some form of modification. [Hayden] stripped the webcam of its case and replaced the enclosure with a piece of acrylic and a mountain of silicone, making it both waterproof and slim enough to fit in the appropriate spot. Though he decided to stick with an Amazon-bought Eheim fish feeder, he disabled the unit’s autofeed timer and tapped in to the manual “feed” button to integrate it into his own system.
It’d take half of the front page to explain the rest of this thing. We’ve decided to let the aquarium tell you the rest of its features in the video below. Yeah…it can talk.
Continue reading “Automated Aquarium is Kitchen-Sinky”
As you start to take in all that was involved with building these two aquariums it boggles the mind. At the time of writing the forum thread is 56 pages long and it’s not just filled up with the adoration of [Big Mr Tong's] fans. He did so much work that every page is packed with progress pictures that cover the range of topics: plumbing, electrical, mechanical, artistic…. wow!
curse project was sparked by a friend giving him a couple of huge acrylic cylinders which were a perfect size for custom aquariums. [Tong] even had a couple of ideas in mind for underwater artwork to fill them with. One is a replica of statue ruins that give you the feeling that the tank is a piece of Atlantis capture for your own entertainment. The other is a fascinating replica of a plumbing stack. You know, the large cast-iron pipes that carry away waste? But these are actually PVC parts with modeling clay accents. They were broken, cut, melted, sanded, and who knows what else, to arrive at this look. The different aquariums feature different lighting techniques. There’s custom-made filter baffles. We could go on and on but we won’t so check out the link at the top for all the details.
In the end he went beyond the original cylinders and built his own square tank for the pipe design. It’s a steam-punk piece so there’s even analog dials to display the vital signs of the habitat.
Just looking to maintain a tank you already own? How about building an automatic chemical dispenser.
We looked through the build log for this in-wall aquarium and were a bit horrified by the before pictures. You look at the original basement photo and there’s wood paneling, an incredibly rusty plumbing stack, and good god what is that wire jumble hanging from the ceiling? But the project’s not about building codes, it’s about the infrastructure that supports this fish tank.
This corner of the basement has a window and the electrical panel in it. It needs to be this big in order to enclose that window, but that offered the opportunity to add in the aquarium while still allowing easy access for feeding and cleaning. Hot and cold water pipes were run over to the location for easy filling. There’s even a drain line running to a utility sink in a different part of the basement for easy cleaning.
This seems like a bit of an upgrade when compared to the coffee pot fish bowl.