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!


Saturday, 2 February 2013

Trapping a Thief

The Thief

Recently, a creature had been stealing my tilapia food. It made a big hole through the cover to gain access. I wasn't sure what it was but all i know is it has strong teeth. I suspect it must be the same squirrel as before.

The hole at the top chewed out by the creature
So, I planned to give it a surprise by cleverly modifying the food container into a trap. I removed all the fish food, and filled the container half way with water. I then soak several plastic bags and a big piece of saran wrap inside the water to give the creature something buoyant to stand on but not rigid enough to allow it to jump out. Once the trap is set, I left it alone for a day.

This morning, to my surprise, the victim was a rat. I was expecting a squirrel. There, it couldn't jump out.

The rat; resting on the plastic bag
The plastic bag provides enough buoyancy for it to stick its nose above the surface while sitting
I released it and hoped that it learns not to come here again. There was a lot of rat poop in the water and it smells like rat. Need to wash the container... ( =_=) viruses... and bacteria...

The Plants

And now, about the plants. The plants...
I found something interesting about kangkong plant. It is very tough. It doesn't give up easily. Last week, when I was clearing the left growbed, I removed all but the top most kangkong vines that were creeping on the PVC shade. The vines, without its roots, soon dries out. But to my surprise, it bloom new flowers!

Dried kangkong vines hanging at the top of the shade
A single white flower (smaller than usual) and several new flower buds at the bottom (not shown)
My tomato and pak choy seedlings are doing well under the new morning brightness. The pruned kang kong is regrowing its shoots very fast. As for the chilli plant, it is going crazy growing new shoots since getting exposed to direct sunlight.

Tomato, pak choy, and kang kong seedlings
Mutant tomato seedling. It remained at the cotyledon stage without growing true leaves.
Centre: Kang kong growing new shoots. Left: Roselle cuttings bought from the market
Chilli plant. The left shoot is growing very fast.
I'm not sure what variety it is. This plant was given to me by a friend. I do not know what is their harvest size.
Another fruit but this one is curled.

Thanks for reading! :-D