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Sunday 28 October 2012

If it ain't broken, don't fix it.

Other than feeding the fish I have pretty much left the system to it's own devices the past week.  The water has cleared up nicely and the fish seem very happy.

They are still wary when I feed them and wait till I stand back before they start feeding.

The basil is doing really well. The rocket on the other hand is reaching for the stars.  The system is located in front of a window in my kitchen but the plants seems to want more light.

I've harvested  some basil  & rocket but I had to be careful not to uproot the whole plant.

The garlic chives & celery are also growing.  If I compare it to the seedlings in the 'real' garden they seem to be more or less the same size. I have read somewhere that it takes something like six months before the aquaponic system settles after which it really starts performing.

Clear water & the plants are reaching for the sky.

Saturday 20 October 2012

Cat burglar

This morning I was disturbed by a noise in the kitchen.  I had some uninvited guests in the past and  these noises always put me on edge.

Anyway, it turned out to be my co inhabitant Caramel.  He was looking for something to eat...

Caramel examining the menu.








As you can see the water is very murky.  I think I overfed the fish and the residue of the flakes is causing it.  I have since changed to feeding them the small floating pellets.
I hope to do a partial water change today to clear the water.

On the bottom right of the tank you will see two indicators.  The Ammonia Alert on the left and the pH Alert on the right.  They provide continues  readings.
They cost about R140 for the pair.  The Ammonia Alert has a lifespan of about a year but the pH Alert's is shorter - can't remember exactly how long now. You can also buy them individually for about R 110 each.  I bought mine at Jungle Aquatics in Broad Acres where I also got my fish.

Thursday 18 October 2012

I should have paid more attention to my science teacher.


You have all heard of a sweet spot?  On a tennis racket it’s somewhere in the centre. It’s that area which gives you the best result for the least effort, something like the 80/20 rule.  Aquaponic systems also have a sweet spot regarding the pH. My system’s pH was in the region of 7.8 and I needed it to be about 6.8.  In the sweet spot the plants have a much greater ability to absorb the nutrients from the water.

So, how do you lower the pH?   The pet shops sell all kinds of expensive potions which generally contain some form of acid. Seeing that we’re all about conserving energy it wouldn’t be economical to do a pet shop visit just for that.  I took the easy option for my kitchen aquaponic setup - I reached for the vinegar.  I popped  a spoonful or two into the growbed and initiated a flood/ebb cycle.  The pH has now dropped to 6.2. Hopefully it will settle in the sweet spot.

I should have paid more attention to my science teacher at school.  There must be some defined volume that would take it to 6.8 . Let me see :- 13 litres water  @ pH of 7.8, final result 13 litres @ pH 6.8, pH of 5%  vinegar (acetic acid) is 2.4. Volume of vinegar needed is ?? - way to complicated. Common sense and some trial & error will have to suffice.

These two photographs are taken one day apart.  It's amazing how much the roots of the plant on the left has grown in 24 hours. (I really need to figure out how to get rid of the reflections.)

If you look closely one can also see the layer of stones between the LECA.  This is to keep the LECA from floating.

17 October 2012 @ 9:43

18 October 2012@ 9:48



Seeds sprouting

Some of the seeds I planted last Saturday have sprouted, a total of four. I think it's the parsley.

 I just had a look at the various seed packets and I see the chives and the cabbage take a bit longer to sprout.

I can't recall how many seeds I put in, but if I get four cabbages and some garlic chives then my growbed is going to be a bit crowded. I'm already dreaming of a bigger system.

Wednesday 17 October 2012

Earthworms

I popped three baby earthworms from my compost heap into the growbed. Earthworms are photosensitive and they quickly dug themselves into the growbed. Now you may ask yourself how can they survive in the waterlogged growbed?  The answer is DO, or dissolved oxygen. The levels of DO in the water is (hopefully) high.  Earthworms don’t have lungs and breathe through their skins. It really doesn’t matter to them if they are in air or in water, as long as there is oxygen.
I am hoping that the earthworms will process any rotting plant material in the growbed, as well as any solids pumped in from the fish tank.

Tuesday 16 October 2012

Seedling transplants doing well

The seedling transplants I did a couple of days ago seem to have taken.  I was worried about one basil plant in particular.  Since yesterday he has been 'heads up'.

I have also been doing water changes, about 1 litre twice a day.  I have been using water from a friends existing pond, as well as water that I have have been aerating using a air pump and a air stone. This is just to get rid of the chlorine in the water. In future I will just put a bucket of water outside and let the sun do the job.

The pH started round 8 and seems to be dropping slowly now. Apparently the fish don't like sudden changes so I will be taking it slowly.

 I am giving the water that I have taken out to my 'real garden' plants.




Saturday 13 October 2012

Name the fish

My two fish are still alive!

As they won't end up on my plate one day I don't mind them having names. It has always been my mom's privilege to name my pets. Seeing that it's no longer an option I'll have to make another plan.

I don't know what gender they are so I was thinking of some gender-less name.  They are also pioneer fish, the first of a new eco system.

I was thinking of something like Alpha Centauri A and Alpha Centauri B, or Alpha Centauri collectively. This comes from Alpha Centauri, a binary star 'close' to us.

Feel free to recommend a more suitable name.

I also dropped in a couple of seeds today - garlic chives, parsley and also a couple of mixed baby cabbages. Only time will tell where the seeds have floated to, and if they actually germinate.

PS.  My Mom would have been 90 today.

Friday 12 October 2012

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.

Wednesday 10 October 2012

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.

Saturday 6 October 2012

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.