Life has begun

Today is the start of life in my system.

I transferred some of my rocket & basil seedlings into the growbed.  This proved to be much more difficult than I had anticipated.  The LECA balls keep on collapsing into the hole. Eventually I got the seedlings in but only time will tell how much damage I did to their roots.  Unless I can get a better method I will have to revert to putting in seeds from the start.

I also put in two goldfish today. According to the pet shop the tank is actually too small for two but we'll see how it goes.  These are the normal pet shop variety - very hardy and they can live in almost any water. At least they look different from one another so I can easily distinguish them.  They already seem to  have unique personalities.

In this photo you will also see the drain pipe coming from the growbed above. Notice the air bubbles. These are generated using the venturi effect. It sound very technical but basically it's a small hole at the top of the pipe.  As the water runs down the pipe, air gets sucked in via the little opening.  This all helps to aerate the water.

System running !!

I eventually finished my system today.  I had to re-work some of the frame as it was not level.

I made a modification to the water level sensor.  For this I used the lid of a margarine tub.  I cut it so that it forms straps into which I slid the two probes. The probes are easily adjusted for height.

The probes are connected to a little circuit board which holds a ATtiny.

What the controller board does is to turn on a relay which operates the pump.  The controller then measures the resistance between the sensors.  As soon as the water touches both sensors, the controller turns off the pump.  This cycle repeats every thirty minutes or so.

I opted to fill the growbed with LECA. Only problem is that it is lighter than water. This means that it starts floating when you flood the growbed.  I overcome this by putting a layer of rocks about 8 cm from the top.  This ensures that the bottom half does not float.

As the growbed is only filled up to a inch from the top of the grow medium, the top portion does not float either.

System build

Today I attended the Aquaponics course and system build at House4Hack.

We were a bunch of about ten, including a father with two of his daughters. It was great to see everyone sharing their tools, skills and time.

Dennis gave an expanded version of the talk he gave at  Software Freedom Day.

Dennis sourced all the components and we basically had to assemble the lot.  This included filing the aluminium strips, riveting it all together, preparing and assembling the drain pipe and then wiring the whole lot together.  I didn't finish mine as my energy dropped to zero by midday.

Dennis has been running a bigger system at home since the end of last year. He has produced more lettuce, basil, tomatoes, cucumbers and strawberries than what his family can consume.

Thanks to Dennis for presenting and also for all the research and buying all the kit  - much appreciated.