This may yet to be proven a perfect eco-friendly food for my crickets before being turned into food for the birds.
Now, time to get more tubs to cultivate these weeds (azolla)
They do not require full sun. Partial shade is preferred. In fact under full sun, it turns brownish. There are much more info on the web regarding Azolla cultivation that any interested parties may want to explore further. However I cultivate mine a little differently. I use AB fertilisers meant for hydroponic farming. At a concentration of 1,200 to 1,500ppm. Lower is still ok. Higher, the leaves turn brownish (2,000ppm)
Received these water ferns (Azolla microphylla) from a friend...
Fast growing like... weeds (what else :D)
Excellent food value. The finches and chicken loves them. Only fear are water borne pathogens. So I soak them in a home made chlorinated water and rinse with tap water before feeding.
How to make food safe disinfectant? Using regular bleach (usually 5.25% available in local stores), and the services of an online calculator, 4ml added to 1L of water will get a solution that is 200ppm (parts per million), which is safe for consumption. Anyway I still rinse them off before feeding the birds.
The below is an excellent documentary on Azolla...
This is the way I use the traditional bottle cup that comes as a set of cups meant for the Oriental white-eye. Fill it to the brim with wax then carve out a little concave cavity. Enough for a single drop of nectar. That way, feeding of nectar can be given sparingly, also the hassle of cleaning the impossible to clean bottle is avoided.
Whether nectar or some other liquid food, I feed undiluted. Diluting with water tends to make the stool watery.
Caution: liquid wax is combustible if touched naked flame, so be careful.
Update (26/01/18):
Oriental white-eye enjoying the drop of semi-liquid food...