I have a very small water feature (millstones in a circular trough) which is suffering from green water. There is just enough room for the water feature pump (which has a course, integrated filter) so I'm looking for ideas on how to manage the green water. I don't really want to resort to chemical solutions. I did look at standalone UV devices which might break down the algae but these all seem to be for installation in a filter - which wouldn't fit.
Can anyone advise of a solution? I'm willing to try an external canister pump/filter but I'd imagine these would all be far too powerful.
Thanks in advance.
