Electronics - Aquaponics - Demand feeder PVC mockup

I think I have a final design idea for my demand feeder. It's only a mockup, at the moment, ie: it's only the PVC parts without any electronics or bearings.

The more I learn about this electronics stuff, the more places within aquaponics I can see uses for it.

I'll do a proper one of my Build posts when I have everything in order, but this is where it's at right now.

The basic design is a 90mm pvc section to hold the electronics (seen at the back or top left).

This keeps the electronics away from the feed and any moisture in a grow house or that just might be splashed around by fish expressing joy at their new feeder.

The electronics section is coupled to a 90mm T-junction to integrate the hopper.

In this case I've used a soft drink bottle, but any sized hopper could be attached. Another option would be one of those office water cooler bottles. Clear so you can see how much feed remains.

Perhaps for ease of refill, the top of a bottle could be cut of to act as a funnel. This could be screwed into the cap allowing the user to simply upend a similar bottle full of food into the hopper funnel.

Finally, the feed is delivered via an PICAXE controlled electric motor, rotating a screw in a 55mm (I think) PVC inner pipe. This holds the front bearing (the rear bearing is the motor, and is housed within the electronics section.

I cut an outlet hole to actually deliver the feed to the fish. I set the hole at the bottom rather than just letting the feed flow out of an open end to avoid water dripping into the feed. This could turn it into a gluggy mess, and jam the system.

The final mockup looks like this.

It'll work.

Not just Electronics - Aquaponics - Demand feeder PVC mockup -  120 Things in 20 years


  1. Hi,
    I'm really enjoying your blog and love all the interesting projects you present and execute. I found a design for a simple, non-electric, stand-alone aquarium aerator, and thought you might be interested. More details can be found here: http://diyaquaponics.com/forum/viewtopic.php?f=88&t=1409

  2. Interesting.

    I remember an episode of TV's "MASH" a few million years ago, where they made a similar device for suction in the operating theatre when there was a blackout.

    I think their system worked by having water in the flask that siphoned out, thus pulling air/blood or whatever it is you use suction for in surgery into the flask to replace the lost water.

    I'm not sure how practical it would be for an aquaponics system, but there are 110 things yet to be done so no doubt it will be one of those useful snippets of head filler. :)


  3. liking the blog and the forum at barkyard aquaponics :) good work mate . i like the decriptive writing you use to explain everything you are doing . keep it up :)


Popular Posts