Posts tagged fish

Aquaponics Project

What’s aqua-what? Hydroponics?

Well, hydroponics is plants in water instead of soil medium. Aquaculture is usually the cultivation of aquatic creatures for food (i.e. fish, prawns, etc). Aquaponics is both together. I think wikipedia has a better description than what I can write (see Wiki entry).

In a nutshell, it’s combining the aquaculture (in my case, Fish) with the hydroponics part. If you’ve kept any fish before, you’d definitely realize that they do produce a fair bit of waste. Otherwise, pet shops won’t be trying to sell you that fancy filter and pump kit plus no matter what, you’d still end up cleaning and changing the water eventually.

Well, let nature do it for you is the name of the aquaculture game. The waste the fishes produce is actually pretty good for plants. So hence my project.

I’ve an outdoor man-made pond with about forty odd Tilapia fishes. They eat and shit a lot. That’s because most of them are edible size by now. Just so you know, these are the 4th generation in my pond (yes, life finds a way to breed) and edible size means over 1.1kg (approx 4.5 lbs). I put a pump in to push the water out into a poly tank what holds hydrokorrels – I can’t find the brand or type I use but this link is pretty close.

The water fills up and gets flushed down and back to the pond. The challenge was that most plants don’t like their roots drowned under water. The roots tend to rot quickly. The solution was inspired by the toilet bowl. Taking some physics lessons, a simple siphon can be created with off-the-shelf PVC pipe parts. This siphon works when the water reaches a certain level. Once the water reaches the right level, it will immediately begin the flush phase where it actually dumps all the water rapidly.

The challenge is to find a fill rate fast enough to trigger the siphon effect but yet slow enough to allow time for the roots to breathe between fill cycles. After some careful tuning, my Laguna 8,000l/hour pump fills my growbed tank in about 10 minutes but dumps the water in 70 seconds.

The diagram is below. Basically the outer 84mm cap is to prevent dirt, leaves and other stuff from clogging the siphon. It does also help you to adjust/tune the water level by creating a barrier to hold the grow bed medium (those hydrokorrels) away from the siphon proper. You won’t need to remove everything just to make adjustments. For the return pipe, the siphon effect is stronger with at least one bend (elbow joint) plus a pipe length of at least half a meter or twenty-odd inches.

Here are my growbed and pond photos.

Adjustment valves to tune the water going into my other filters/hydroponics troughs and the growbed. My 8000L/hr pump is too powerful for a single growbed at the moment.

The return valves/pipes into my pond.

Sweet basil, Thai basil, Mint, rosemary and spinach growing nicely.

The siphon assembly.

My basil and 3 day-old spinach plants. Spinach grows pretty well and fast. I get to harvest them every ten days.

My Tilapia fish. Hardy and dirty. Just what’s needed for the plants. They’re edible too and fast growing.


South Sea Subang

Celebrated my mom’s birthday at a cozy little seafood restaurant in Subang called South Sea. In some ways, it’s set up close to what some termed the “death row” considering that you pick your fish happily swimming away in their little glass aquariums. They then end up on your dinner plate and your stomach! Of course the selection available is smaller than a similar restaurant we went to in Kota Kinabalu, Sabah called Ocean seafood but then, again, it’s close to home and had good food, reasonable prices and most of all, super fresh. Here are some of the “inmates” on the “death row”…

A 900km sunrise to sunset drive

And also why I really need a small camera (The Lumix GF1 comes to mind… my Birthday is coming you know)…

Anyways, it was an interested drive down south and into areas unknown. While the highway stretches were ridiculously boring (how exciting can highway driving be), there was a short stretch of about 15 kilometers of plantation track where going at dust storm churning rally speeds provided a bit of thrill. All for a bit of fresh (live) fish. Really awesome considering that they survived the trip home. Well, not every fish though, just the ones we wanted. The rest were mercilessly packed into ice. Surprisingly though, they survived till the Pagoh rest stop, or maybe beyond, I don’t know as some were still flapping around at the stop. Probably expired between Pagoh and KL but I wouldn’t know.

Fresh as can be…

I’ve always wanted to post this earlier but with post-Christmas feasting (or was it pre-New Year), then New Year’s eve and more festivities getting in the way, it was tough. Then of course all the pre-Chinese New Year to-dos and what-nots, the Lunar New Year is a lot earlier than normal and it is really a bit tiring. Fresh food has always been a hallmark of Chinese cuisine. I think in the rush for industrialization, we are really missing all that sort of stuff that our ancestors used to enjoy, like garden fresh vegetables, and succulent fresh fish right out of the lake. In our case, it’s right out of a tank but it doesn’t get better than this!