Algae is a problem in ponds. My son had a large fish tank and algae was a problem. I had an EHEIM UV filter, that effectively gets rid of floating algae but as the member HSW correctly stated above, Hair Algae will still survive. Obviously, a pond is much more difficult to manage.
Algae spores are everywhere and naturally it will grow. No way to prevent it. One possible way to minimise the algae growth is to reduce the sunlight. If you grow plants that cover the surface by at least 60% of the pond area, then it will be quite effective.
There are algaecides, even though some are marked safe for fish and frogs, I am not so sure about these. In any case you got to be quite careful with the quantity used.
There's a safer additive using bacteria and diatoms, but I am not sure you can get them. These bacteria will remove the excess food in the pond and will compete with the algae, thereby controlling it.
wedak ne. okun loku unama minissu gagata danawa. hena kalakanni wedak ekanam
