thanks for the response.
I kept filtering and shocked again yesterday to maintain the chlorine high. The pool is still cloudy, I can barely see a foot below surface. I can confirm the water doesn't look green, it was milky to start with, now it looks more grey-ish. But when I wash the cartridge there's a lot of milky stuff coming off, so that should be the dead algae.
I live in the UK so I guess renting the robot is not an option unless they do it here
Once I'm back from work today i'll start the vacuuming, when I did it a couple of weeks back my cartridge was immediately blocked by debris and i lost suction but things may have improved now.
Need to resolve this soon, I'm at my wits end having spent lots of effort and money while struggling to keep my family patient