self sufficient life

Almost free heating

We have found the perfect home and can’t wait to start moving. The place is currently empty, so we could have moved in when we first saw it 3 weeks ago. All the paper work, however, takes time and real-estate agents and bankers who are on holiday make the waiting time even longer.

I’ve been doing some thinking on space heating and DHW heating for the place. The property contains a big greenhouse complex consisting of 8 greenhouses, totaling over 6000 square meters. We wanted a big greenhouse, but this is way more than we are going to use. When checking out the place, one of the greenhouses had all its windows closed and it was unbearably hot in there. This got me thinking, the property has a huge heating system, which is designed to heat all of the greenhouses. The space heating for the house is just t-ed off of the big heating system, but since we are not going to use much of the greenhouse space to begin with, firing up this monster heater just to heat the house would be a big waste.

What if we can store the heat from the greenhouse for later use? One greenhouse would just function as a huge solar panel with water flowing through tubes and back to a big heat storage tank. A 20.000 liter oil tank, which is already there, can probably be used as the heat storage tank. I would only need to insulate it and run some pipes from the greenhouse to the tank.

I have no idea how much the greenhouse will heat up on a sunny winters day, but I will probably need some supplemental heating. If you have a big heat storage tank, you can use several heat sources to feed it. I will probably install a wood burning stove right next to the heat storage tank, to ensure we don’t freeze in winter. Heat generated by a Lister engine can also be fed into the same heat storage tank.

I found builditsolar.com to be a great resource on DIY solar projects. If you want to know more about wood stoves for heating, you should check out the forums on heart.com

Worm composting

If you want good soil for your vegetable garden, flower beds or potted plants, without having to pay for it, composting is what you should do. I’ve had a big compost bin standing in my garden for quite a while and it does a great job, but it takes ages to turn my kitchen scraps into good compost. These big compost bins rely on bacteria to break down the scraps and they will take between 6 months and a year before you can use the compost.

Worms however can compost a lot faster. While digging in my garden I found a good number of worms which I have added to my compost bin to speed things up. When I recently decided to move my compost bin however, I found no worms in it. After a few weeks of hot and dry weather the worms all dug down into the soil beneath the bin and where gone.

If you want to compost with worms, which is also called vermicomposting, you need a different kind of compost bin. A worm bin will have a closed bottom, so the worms can’t get out. You do have to drill a couple of holes into the bottom, so excess water can get out. You can use any type of plastic bin for worm composting, but ideally it will have a matching lid. Worms breath like all animals so you need to make sure they get enough air. A few slits or holes in the side of your bin will take care of the air circulation, but you want to cover them up with some screening to keep flies out.

Fill your bin about half way with moist newspaper or cardboard strips and add a layer of soil. If you have a compost bin you can probably find some worms in there or you can do some digging in your garden. You can also go the easy way and buy some composting worms in a garden center or order them online.

Keep your worm bin out of the sun and make sure it stays moist. The worms will accept temperatures between 10 and 30 degrees centigrade but will do best at around 25 degrees. Be careful not to overfeed the worms or your worm bin will start smelling bad. Don’t add any scraps until the last batch has been eaten completely and always burry the scraps you are adding. In time you will get a feel for the amount of scraps your worm bin can process.

Aquaponics Lettuce and Basil

My aquaponics system with expanded clay granulate is doing good. The lettuce I have planted in there hasn’t grown too much, but the plants are looking good and seem to start growing now. The reason why they haven’t grown until now is because there weren’t enough nutrients in the water. When you want to grow something in a new aquaponics system, you have to let the system mature for a while and give the nutrients time to build up a high enough level to sustain your plants. I’m the impatient type and can’t wait for maturing systems when trying new things, so I planted way too soon. Things are looking good now however, so it’s all good!

I have also put a cutting from a basil plant into the grow bed and planted some basil seeds. The cutting was cut from a basil plant that I bought from the supermarket and lives in my kitchen window. I just cut a piece and stuck it into the clay granulate. Two weeks later the cutting still looks good and it has grown some impressive roots! The basil seeds have sprouted too.

The property hunt is on

With the summer holidays approaching, I think now is the best time to pack our stuff and move, so the kids can transfer to a new school when the new school year starts. We have been searching for a suitable location for a while and I think we have found just the right spot. The property we are looking at has 10.000 square meters of land in the middle of nowhere, the nearest neighbor is about 400 meters down the road, yet all important facilities like doctors, schools and stores are only a few car-minutes away. The property also includes a 340 square meter barn which would be perfect to house the little company we are planning. We have an appointment with the real estate broker next weekend and we are so excited about it that we have trouble sleeping!

Aquaponics, take 3

With some help of the nice people over at Backyard Aquaponics, I now know why my tomato plant didn’t grow. The gravel I was using as grow bed medium was the wrong type of stone, probably limestone or marble. This caused the pH of the water to rise up to 9.0 and inhibit the plants nutrient uptake.

They say that lessons learned the hard way stick better, I agree. Before getting the next trunk load of gravel and take half a day of washing it and shoveling it into my grow beds, I will take a sample home to test. I’m quite sure I will not forget to do that!

Well, back to aquaponics, square one. I got a bag of Seramis expanded clay granulate to use as grow bed medium. This stuff is specially made for plants, so it should do the trick. It is a lot more expensive than gravel, but it has a few advantages: the very porous material is very lightweight and the capillary action will suck the water up for quite a few inches. Because of this it can be used in a constant flow system with a constant low water level, so no more messing around with loop siphons. I used a small square container as grow bed. A hole in one corner is covered with a drain sieve which prevents the clay granulate from washing into the fish tank.

I’ve planted some lettuce into the grow bed and threw some basil seeds in. Stay tuned for their progress!

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Compost vs. Aquaponics

Almost 4 weeks have passed since I set up my aquaponics system and planted a little tomato plant in there. Another seedling from a seed of the same tomato has been planted into compost which I have enriched with cow manure. The plan was to compare the total yield of both plants, but there is nothing left to compare.

The aquaponics plant has not grown at all in the 4 weeks. The only difference to how the plant looked 4 weeks ago is the color: the plant is now purple, which is a sign of not enough nutrients and too much water. I guess I planted too early. I will let the system mature a little longer and try again in about a month.

The plant in compost is doing very well. It has grown tremendously in the last 4 weeks and looks very healthy with juicy leaves and a thick stem. Even the Lego minifig I placed into the pictures for size comparison noticed the difference and wanted to stay in the compost veggie-garden.

For now the score is: Compost 1, Aquaponics 0. But I expect this to change once the system has matured…

Breeding birds in our garden

Our garden is swarming with life. We hear little birds all day from all directions. Most bird nests are well hidden in tall trees or dense shrubs, but if you provide the birds with a suitable nesting location you can place it somewhere where you can watch the little ones grow up and fly out. We got a pair of great tits in our birdhouse and after seeing the parent birds fly on and off with food for the little ones for a while, they where ready to spread their wings today. We watched 6 little birds come out of the birdhouse and fly away into the big world.

Free Fish Food

Daphnia (a.k.a. water fleas) can be bought at most aquarium shops, but what if you could get them for free? These tiny crustaceans are really easy to breed. In the summer months you can simply put a bucket filled with old aquarium water in a sunny place and they will have enough food to thrive and you will have a constant supply of free fish food.

I filled a 250 liter rainwater barrel with aquarium water and put some fish food in there every few days until I had a nice algae bloom.

I went to the aquarium store quite a few times, but each time they where out of life daphnia, I used too see them there every time, but now that I needed them they didn’t have any… typical…

Eventually I managed to buy a small bag. I put them in the green water and after only two weeks the water was crystal clear and swarming with daphnia. Every day I can scoop some out to feed my fish but the supply seems endless.

During winter the barrel froze over and I thought that the water fleas had probably all died, but to my surprise they continued breeding when spring arrived.

If you want to have live fish food during the winter as well, you can set up a culture vessel inside, but you will probably have to feed them.

Square Foot Gardening

Our kids are never playing in the sandbox because of the bugs and spiders that get in there, so today we got the sand out to try something new. Since the contents of our compost bin wasn’t ready to use yet, we went into the forest to get some good compost. We filled the sandbox with it and used some rope to partition the square meter box into 9 square feet patches.

Each square has been planted with a different crop. We have planted: four heads of lettuce, one tomato plant, one cucumber plant, four cloves of garlic, some rosemary, thyme, a sunflower and two patches with some different flowers.

The size of one square meter is perfect for our 8 year old daughter to walk around and be able to reach every part of her garden. This system was taken from the book All New Square Foot Gardening by Mel Bartholomew and it supposedly lets you grow about twice as much in half the space compared to traditional gardening, while only requiring about 20% of the work.

Solarpower Breakthrough at IBM

You probably know how you can use a magnifying glass to concentrate solar power into a small spot and start a fire. The solar power researchers at IBM have taken it a step further and managed to concentrate incoming solar energy by a factor of 2300, equaling about 230 watts of power on a square centimeter. This energy could then be converted into about 70 watts of usable electric energy. The biggest problem with concentrating the suns rays this much is that it heats the solar cells to about 1600 degrees Celsius, which would melt them. IBM however is an expert at cooling high power computer chips and managed to keep the solar cells at a ‘cool’ 85 degrees Celsius!

Read IBM’s press release here