We leave in a tropical climate, been away for 4 months come back to a pool water a bit green but the bottom floor is covers with green algae which is so hard to scrum off.

I would pressure wash first, Bleach solution may be needed after, not sure of amount and the application.

In ground, above ground, vinyl liner or cement?

Ground cement

What have you tried so far?

Shock treatment 2 cup twice a week, Algae blow out treatment once last week. Scraping small areas with steel brush, When water is clear and debris settle at the bottom vacuum twice a week. Kept topping up with chlorine.

Yeah, I hate cleaning my swimming pool :-( It sucks!

One day I will get rich and buy myself one of these robotic pool cleaners (http://www.purepool.com/pool-cleaners/robotic.html) :-))) Wonder if this day will ever come. Until then I will have to do all the nasty work by myself :-((