I guess your algae is seasonal? If so something like DAF as Bimr suggests can be switched on an off much easier than sand filters or diskfilters, but if you use polymer, be careful not to get carry over ontyo your SSF's. Disk filters are ok, but you I certainly wouldn't use 10 micron, 20 will give you a longer life. With disk filters you will need to carry out a chemical clean (phosphoric or hydrocholic acid followed by hypochorite) a coule of times a year. Disk filters would need to be sized 150% of max flow as performance can decrease quite quickly and limit your supply.
Have you thought about a small ozone plant up stream of a rapid filter or strata sand filter?