Over the last two years, I've had minor hard green spots in the spa which I simply scrubbed and then shocked. They typically return several months later. Now I'm starting to see some spots in the pool and also in the pool equipment, such as the hose in the pool (although appears to be softer). Overall the pool is always clear. I haven't had an algae bloom in years.
This is a salt water pool. I use Pool Perfect with PhosFree about every two weeks.
Suggestions how to get rid of this hard algae stuck to the sides and now in the equipment?