Whilst researching the biogas and building the ponds for our tilapia, I came to realise that water plants and weeds were ideal for both feeding fish, and for feeding the biogas units. I don’t quite know which came first – food for tilapia or waste for biogas, but I stumbled upon quite a few exciting discoveries whilst doing my research.
Tilapia are herbivorous – in other words they eat plant matter, unlike carnivorous fish. So pondweed was actually an ideal nutritious food for them, which grows rapidly on ponds and still water. I watched several youtube videos about how tilapia breeders were harvesting tanks full of the stuff, and no matter how much they took out of the tanks, more seemed to take its place instantly.
Perfect! Free food for the fish, and a huge reduction in rearing costs as a result….
As luck would have it, just outside our house in Norfolk was a pond which was at the beginning of the Norfolk Broads. The pond contained still water, and we often saw the resident moorhens chomping away at the weed blanket. So I extracted some pondweed and sent it to Spain in containers, to reproduce it here.
At the same time, I searched the internet for oxygenating weed, and bought some of ebay to bring over too. It was then that I spied a plant called Water Hyacinth. What caught my eye was that it was ideal for putting into biogas units.
I became fascinated by this plant. Apparently it is an environmental problem of enormous proportion in many warmer countries, where it spreads rapidly, choking up waterways, silting them up, and turning them into swamplands, and devastating fishing communities. As fast as they take it out of the water, more plants take its place! JCB diggers are being used to try and remove this invasive plant from the water, working 24 hours a day with no success. And the plant is prohibited in many countries, including Spain.
I just had to have some…..it would be contained in our ponds, provide perfect cover for the fish, and provide an endless supply of fodder for the biogas unit!
Isn’t it weird? Where some people see problems, others only see solutions or advantages. Could we really provide people with free gas, using a natural, never ending supply of fodder? Could they convert all this free waste into free biogas and store in into huge tanks, like ordinary gas? Wouldn’t that be something?
Back to ebay….
Soon, the plants all arrived at our home in Spain. I decided to put some in tanks, some in the ponds, and some in buckets – just in case one lot didn’t flourish.
Then I waited. And waited, and waited.
After several weeks, virtually all of the duckweed, oxygenating weed and water hyacinth had died! No matter what we did – added nutrient to some of the containers, Raised the temperature in some, put some in the greenhouse, some outside….nothing worked. IO got more duckweed sent over. That all perished too!
I just can’t believe that we cannot grow these invasive self propagating plants, and will keep on trying until the end of my days – back to ebay….
We’ll let you knows how we get on – and if anyone has got any tips on how to grow these water weeds, please let us know!
To read more about the progress of our Spanish Dream Click Here