fish

46 Articles

Engineering Micro-Submarines To Replace Fish

July 1, 2026 by 14 Comments

Everybody loves aquariums. There’s something soothing about watching the lil’ critters inside them swimming, crawling and wriggling about. But at the same time few people are up to the task of ensuring that said critters stay alive and happy in said aquarium. This is where small robots may be able to steal some fishy jobs, like a modern take on the gaudy fake aquariums of the 1990s. Cue [CPSDrone]’s mini-drone aquarium with mostly maintenance-free robotic fish.

These pose a few interesting engineering challenges, such as the replacing of feeding fish by having them scuttle back to their charging station like an aquatic Roomba, and giving them some level of intelligence to the point that they at least appear to be doing something fish-like.

Rather than give each robot fish full autonomy, they are instead controlled by a central system. This then raised the problem of radio frequency communication while underwater. The theory was that 433 MHz transceivers would still work for something the size of an aquarium before attenuation spoils things, which a quick test confirmed to be true.

This enabled the construction of a small microcontroller-carrying submarine as a proof of concept before diving into the final version, involving resin 3D printed enclosures that are made water-tight using rubber O-ring seals and UV-cured resin. All that was left now was to add the big control system, which takes up much of the rest of the video.

Sadly they didn’t implement the boids algorithm, as this is pretty good at creating realistic life-like motion, as show with this demonstration by [Ben Eater]. This algorithm is pretty simple, with each ‘creature’ obeying rules on coherence, separation and alignment, creating a pattern that can be observed among schools of fish as well as flocks of birds. Due to its simplicity you could conceivably even omit the central control system and just give each ‘fish’ enough sensors to keep track of its buddies.

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Fish Drives Tank

March 1, 2026 by 13 Comments

Fish are popular animals to keep as pets, and for good reason. They’re relatively low maintenance, relaxing to watch, and have a high aesthetic appeal. But for all their upsides, they aren’t quite as companionable as a dog or a cat. Although some fish can do limited walking or flying, these aren’t generally kept as pets and would still need considerable help navigating the terrestrial world. To that end, [Everything is Hacked] built a fish tank that allows his fish to move around on their own. We presume he’s heard the old joke about two fish in a tank. One says, “Do you know how to drive this thing?”

The first prototype of this “fish tank” is actually built on a tracked vehicle with differential steering, on which the fish tank would sit. But after building a basic, driveable machine, the realities of fish ownership set in. The fish with the smallest tank needs is a betta fish, but even that sort of fish needs much more space than would easily fit on a robotics platform. So [Everything is Hacked] set up a complete ecosystem for his new pet, making the passenger vehicle a secondary tank.

The new fish’s name is [Carrot], named after the carrots that [Everything is Hacked] used to test the computer vision system that would track the fish’s movements and use them to control the mobile fish tank. There was some configuration needed to ensure that when this feisty fish swam in circles, the tank didn’t spin around uncontrollably, but eventually he was able to get it working in an “arena” where [Carrot] could drive towards some favorite items he might like to interact with. Mostly, though, he drove his tank to investigate the other fish in the area.

The ultimate goal was for [Everything is Hacked] to take his fish on a walk, though, so he set about training [Carrot] to respond to visual cues and swim towards them. In theory, this would have allowed him to be followed by his fish tank, but a test at a local grocery did not go as smoothly as hoped. Still, it’s an interesting project that pushes the boundaries of pet ownership much like other fish-driving projects we’ve seen.

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Billy Bass Gets New Job As A Voice Assistant

October 9, 2025 by 8 Comments

For those who were alive and conscious before the modern Internet, there were in fact things that went “viral” and became cultural phenomenon for one reason or another. Although they didn’t spread as quickly or become forgotten as fast, things like Beanie Babies or greeting a friend with an exaggerated “Whassup?” could all be considered viral hits of the pre-Internet era.

Another offline hit from the late 90s was the Billy Bass, an absurdist bit of physical comedy in the form of a talking, taxidermied fish. At the time it could only come to life and say a few canned lines, but with the help of modern hardware it can take on a whole new life.

This project comes to us from [Cian] who gutted the fish’s hardware to turn it into a smart voice assistant with some modern components, starting with an ESP32 S3. This chip has enough power to detect custom “wake words” to turn on the fish assistant as well as pass the conversation logic to and from a more powerful computer, handle the audio input and output, and control the fish’s head and tail motors. These motors, as well as the speaker, are the only original components remaining. The new hardware, including an amplifier for the speaker, are mounted on a custom 3D printed backplate.

After some testing and troubleshooting, the augmented Billy was ready to listen for commands and converse with the user in much the same way as an Alexa or other home assistant would. [Cian] built this to work with Home Assistant though, so it’s much more open and easier to recreate for anyone who still has one of these pieces of 90s kitch in a box somewhere.

Perhaps unsurprisingly, these talking fish have been the basis of plenty of hacks over the years since their original release like this one from a few years ago that improves its singing ability or this one from 2005 that brings Linux to one.

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Automatic Feeder Keeps Fish Sated

September 23, 2025 by 3 Comments

[Noisy Electrons] is a maker who also likes to keep fish. He sometimes needs to travel and keep his fish fed in the meantime, so he created an automated solution to handle that for him.

The build is based around an STM32 microcontroller, paired with a MCP7940N real-time clock to keep time. The microcontroller is hooked up to a few buttons and a small display to serve as an interface, allowing the feeding times and dosage amounts to be configured right on the device. Food is distributed from a 3D printed drum with a hole in it, which is rotated via a stepper motor.  Each time the drum rotates, some food falls through the hole and into the tank. Dosage amount is measured in rotations — the more times the drum rotates, the more food is delivered to the fish.

[Noisy Electron] built three of these devices for three separate tanks. Thus far, it’s been three weeks and all the fish are still alive, so we’ll take that as a vote of confidence in the build. We’ve featured some other great pet feeders over the years, too Continue reading “Automatic Feeder Keeps Fish Sated” →

This Arduino Is Feeding The Fishes

May 1, 2024 by 7 Comments

Depending on the species, a fish can be a fairly low-maintenance pet. But of course even the most laid back of creatures needs to eat, so you’ll have to make sure to feed them regularly. If you’re a fish owner who would like to simplify tending to your creatures, you might find value in this project from [CrazyScience].

This fish feeder is based on an Arduino Uno, the 8-bit microcontroller development board which has done so much for so many. The Arduino drives a stepper motor, which rotates a 3D printed disc mechanism for dispensing food. Each slot of the disc is loaded with a small amount of fish food, so that when it rotates, a slot dumps its contents through a slot into the water.

Activating the system is as easy as a wave of the hand. That’s thanks to an ultrasonic sensor, which detects movement close by, and triggers the food delivery mechanism in turn. We’d love to see this upgraded with a timer mode too, though it would require the addition of a real-time clock module to the humble Arduino Uno.

It’s a simple project, but one that teaches all kinds of useful skills, from programming to design and 3D printing. We just worry that the fish bowl in the demo is a far too small for fish to remain healthy. We’ve seen some other similar projects before, too.

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No Fish Left Behind

July 25, 2023 by 25 Comments

For hundreds of years, Icelanders have relied on the ocean for survival. This is perhaps not surprising as it’s an isolated island surrounded by ocean near the Arctic circle. But as the oceans warm and fisheries continue to be harvested unsustainably, Iceland has been looking for a way to make sure that the fish they do catch are put to the fullest use, for obvious things like food and for plenty of other novel uses as well as they work towards using 100% of their catch.

After harvesting fish for food, most amateur fishers will discard around 60% of the fish by weight. Some might use a portion of this waste for fertilizer in a garden, but otherwise it is simply thrown out. But as the 100% Fish Project is learning, there are plenty of uses for these parts of the fish as well. Famously, cod skin has been recently found to work as skin grafts for humans, while the skin from salmon has been made into a leather-type product and the shells of crustaceans like shrimp can be made into medicine. The heads and bones of fish can be dried and made into soups, and other parts of fish can be turned into things like Omega-3 capsules and dog treats.

While we don’t often feature biology-related hacks like this, out-of-the-box thinking like this is an important way to continue to challenge old ideas, leave less of a footprint, improve human lives, and potentially create a profitable enterprise on top of all of that. You might even find that life in the seas can be used for things you never thought possible before, like building logic gates out of crabs.

Thanks to [Ben] for the tip!

Fish Tank Dosing Pump Built Using Pi Pico

March 17, 2023 by 5 Comments

When you’re maintaining a fish tank, it’s actually quite important to get all your basic chemistry right. Mismanage things, and you’ll kill all the helpful bacteria in the tank, or kill your fish when things get too alkaline or too acidic. To help him get things just right, [yojoebosolo] built a custom dosing pump to maintain his fishtank.

The pumps themselves are small peristaltic pumps sourced from AliExpress. They can be had for under $10 if you look hard enough. Two of these are assembled into a PLA housing. Meanwhile, the brains of the operation is a Raspberry Pi Pico. It’s charged with running the pumps to a regular schedule, ensuring that just the right amount of chemicals are delivered when they are needed. It delivers 2 mL of Kalkwasser solution into [yojoebosolo’s] reef tank every ten minutes.  The pumps are switched on and off with a simple 5V relay.

If you’ve got a delicate and complex fish tank that demands only the best, building your own dosing pump may be the way to go. Off-the-shelf versions can be expensive, after all, so sometimes it makes sense to roll your own. Video after the break.

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