Friday, 15 February 2013

DIY On Demand Feeder

Last week, during Chinese New Year, I had to visit my hometown in Malacca for 5 days. Feeling worried that my fish will starve (perhaps even die) during the holidays, I quickly made a simple on-demand fish feeder out of materials available in my house before I begin my trip. The design is based on several DIY videos I found on youtube and some aquaculture PDF files that can be googled.

Though my design was based on the commonly used pendulum demand fish feeder, the food release mechanism works differently. The usual design requires the pendulum rod to be extended below the surface of the water so that the fish can activate the food release mechanism by bumping the rod. The problem is that my rod is made from iron and is slightly galvanized. Since I can't have the rod touching the water, I tied a string to the end of the rod and attached a ball of cotton rope at the bottom end of the string which floats on the surface acting as bait. When a fish bites and pulls the bait, the whole feeder shakes, releasing some pellets in to the water. Once the feeder was set up, I left my house with my fingers crossed in hopes that my tilapia will soon learn how to use it.

When I returned home, 5 days later, I found the feeder empty. The fish seemed happy, but I wasn't sure if the fish had learned how to use it yet. I refilled the feeder and stood in front of the tank for 30 minutes to see how the fish "use" it. Most fish just nibble or "kiss" the bait but occasionally a clever fish (perhaps just hungry for a bite) will pull and jerk it hard enough to release enough pellets to feed several fish. The feeder works!

The way my feeder works is by taking advantage of tilapia's feeding behavior. When they feel hungry, they will start nibbling on anything they can find. The ball of white cotton rope with its hairy cotton strands looks attractive (at least to me) to them. Pulling the bait hard will shake the feeder which releases pellets in to the water where the fish can snack on. When the tilapias are full, they are less likely to nibble the bait. This way, feeding times will be much more regular which I hope will increase their growth rate and also provide less stress to the filtration system.

Hopper made out of mineral water bottle.
The disc is made out of a piece of thick paper with a bottle cap below it secured by rubber band.
Bait made out of a white cotton rope.

As usual, I will also include several photos of the plants...


Tomato (12" tall).
Bok Choy seems to be having iron deficiency.
Red Okra having problems standing upright due to the recent rain.
Roselle cuttings at the left and flowering kang kong plant at the right.
Fruiting chilli plant.

Thanks for reading!



  1. Hi Lim,

    I've come by your site thru search engine and quite excited to try out my very own back yard aquaponic too!

    I was wondering whether you are able to guide me thru the process of setting up the sloth metal frame? I had order my blue fiber tank and is expecting to receive next week, thou i still consider whether to use rain gutter for grow bed or get another blue fiber tank.

    Can we meet up to discuss about setting up aquaponic system?

    I'm working in kemuning area, perhaps we can have a tek tarik session or something? i can be reach at zero one seven 928 6933.

    Hope to receive your guide and advise soon.


    1. Sorry for the late reply. I neglected my blog for a while. :P

      Yes, I'm willing to give you guidance.
      I've sent you an sms.

  2. That feeder you made is great work.

    1. Thanks!

      It also made me lazier since the tilapias had been feeding themselves now. :D

  3. Simple n genious fish feeder :)

  4. Thanks. I will try this on my small kois. They seem to be hungry most of the time though.