Sump Cleaning Questions

I have been running my sump for about 10 months now (ecosystem 3612 sump) for a 125 gal tank. I keep it clean but my two questions are:



1) How often should I clean the return pump and skimmer pump? Both are operating fine still, intakes are clear and I have nice coralline algae growing on them so I hate to clean them off with vinegar.



2) Should I rinse off the spaghetti algae with RO/DI water?



Thanks!