Joe McCrohon

Hi all
I'm investigating growing Chlorella Vulgaris to eat in an earthship. The water would come from a rainwater harvesting system. The tank containing chlorella would be next to an aquaponics system containing fish and salad crops. What I want to know is that given that the water will be close to a neutral PH what measures do I need to put in place to avoid contamination by other unwanted organisms, such as harmful cyanobacteria or salmonella and how much do I need to sterlise the rainwater harvesting system? Also do I need to avoid cross contamination between the aquaponics and the chlorella. Also  are there any methods that make it easy to tell if contamination has happened?

Hi folks, the community garden I'm working on gets very wet in winter but also rather dry in summer, I was therefore thinking that a grass that likes wet conditions could be grown in winter and then used as a mulch in summer when things are drier but which grass should I use? for reference I live in the south of England. Also it would help if it was reasonably fast growing.

I have a flower growing on my allotment and I wondered what it is? The flower is the one with the circular heads