Azolla production

I have been reading all sorts of good things about the food value, for fish, of the water fern azolla. It contains quite a lot of protein in the dried state and has been used in lots of places around the world as a protein supplement in livestock production. The most interesting thing about azolla is that it can double its mass every few days when provided with the right conditions. I had a few failures in trying to get a culture going but am now producing quite respectable quantities on a daily basis. This is scooped out of the pond and dried on a rack which is simply flyscreen over a bit of steel mesh. After a day or so of drying I rub it through a sieve and now have about 9 or 10 litres of dried leaf. As the water content of the living plant is about 95% the 10 litres of dried leaf represents probably 200 litres of fresh azolla. And that was all produced in the 1200 litre stock trough outside the shed over about a month or so. This little plant grows like a weed when given the right conditions.
To start the culture the trough was half filled with water and a couple of biscuits of hay and a handful of super phosphate was added. This creates an algal bloom which was actually planned as a starter food source for mosquito wrigglers and daphnia. I got quite a few feeds of wrigglers and daphnia for the fish but then in a moment of weakness chucked in a few handfuls of azolla. The water in the trough became so covered with azolla that I no longer get a harvest of live food for the fish.

So I have now created a new area where I can grow azolla and this will free up the big trough for live food production. The dried leaf will become one of the ingredients of my homemade fish food - more about that later.

The new area is made up of 6 half blue barrels each of 100 litres - the total volume is about 600 litres and the total surface area is about 3 square metres. These have been seeded with hay and/or super and should be going green within a few days . I plan to start adding chicken litter and droppings in the new areas as an experiment. The overall plan is for as many of the inputs to the system to be home grown- sort of a permaculture system where one areas waste is another areas nutrient.

The pieces of shadecloth in the water are there to give lizards, which seem to want to get into the barrels all the time, something to climb out on. Before the shadecloth went in I inadvertently trapped several of the Cunninghams skinks which live near the shed. Fortunately the water was not deep enough at the time to drown them and they survived.