Aquaponics - On demand fish feeder

A while ago I tried to make a fish fed fish feeder design that would allow the fish to feed themselves.

I think It's made.

I say "think" because the fish have only triggered it twice in its first 12 hours of it being set up in their tank, and it's too early to tell if it works.

I bought a small 12 volt electric motor and gearbox, and connected it to an old drill bit from a hand cranked wood drill.

I cut a section of PVC pipe lengthways as a feed hopper, and filled it with feed.

The gearbox on the motor means the output shaft spins at only 36 revolutions per minute, and is quite powerful.

The next step was to find a switch that was very delicate to operate, so the fish could just lightly touch it to activate the motor.

I found a suitable lever switch, and glued on a plastic knife to extend the lever down into the water.

Now if the fish touch the lever, the motor engages, rotating the drill bit, forcing a small amount of feed along the PVC hopper into the fish tank.

I added a key, and a clip from my office as additional weight to set the trigger closer to being activated so the the fish need not hit the lever so hard.

It does actually seem to work, and the fish have set it off twice so far.

Only time will tell if it will really work as a feeder, or if every now and again, a fish just bumps into it and never associates the drop of food with the press of the lever.

[Note from the future - there is a LOT more to this project in later posts, including a new digital version where you can set the total amount of feed from a pinch to a bucket, and a stack of other features including a dawn reset so the fish can live on natural time rather than Greenwich imposed human time - there is also a video of the fish feeding themselves, and here is the results of a search on this blog for fish feeder for a stack more information]


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  2. How did you train he fish to press the switch? or is that just a matter of serendipity?

  3. I thought I was going to have to press the lever myself when ever they got close. Then only press it when they got closer etc until they got the idea, but it turns out they just investigate anything new by pecking at it.

    They figured it out within a few days all on their own.


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