I have acid washed my pool a couple of times and the results were not good. I saw streaks where the acid went and still got algae back. This time a pool guy said we should pressure or power wash it. The pool was bad. The water was green, the sides were black and the bottom was slimy. We couldn't keep the chlorine up. The in floor jet system was getting junk caught in the screen.
The pool guy replaced our DE filters and fixed our backwash valve (which you are supposed to grease every time you backwash). We then drained the pool using a sump pump since the normal pump couldn't keep a vacuum to get all the water out of the bottom. We had to finish emptying the pool using the neighbor's shop vac. Then my wife decided to use a bug sprayer filled with chlorine on a mist setting to spray the sides (don't breath it or get too much on your skin). She then shot the sides with a 3000 PSI pressure washer with a 40 degree nozzle. She said she had to repeat this 3 times but the pool looks great.
The pool is 20 years old and apparently plaster is only supposed to last 12 years so we lost more plaster and the pool surface is rough. The roughness makes it easier for algae to form.
