Pool turned cloudy after robot cleaning

[supersub]

Our in-ground saltwater pool was built and filled last summer, even though the surrounds continued to be a building site. It was uncovered over the winter, resulting in leaves and sand/dust on the bottom.
Earlier this month the water was perfectly clear, despite the debris on the bottom, proving the pump and filter had been doing their job. However, one of the builders decided to try out his new cleaning robot on our pool just before we arrived for the summer. This removed some of the debris from the bottom of the pool, but ever since it has been cloudy.
The water has been circulating and we have tried vacuuming the pool, and we have seen a lot of dirty water removed by backwashing, but the water in the pool is very slow to clear. In sunlight, you can see particles floating in the water.
Any thoughts?

[Denniswiseman]

The robot probably stirred it all up. You need to get as much debris out of the pool with a net and if possible vacuum to waste
Then get your numbers checked
FC:
TC:
pH:
TA:
CH:
CYA:
Salt:
What type of filter do you have and you probably need to backwash quiet a bit

[supersub]

Thanks, Dennis. Such a beginner that I don't even know how to find those numbers, though the box on the wall says 9!
There doesn't seem to be anything large left in the pool - only tiny particles. Backwashing does seem to be clearing some of the muck, but it's a slow business. Our builder (who now massively regrets letting his mate put the robot in the pool!) says he will try some chemicals to clear it.
It's a shame as it was perfectly clear before, albeit with stuff on the bottom...

[Denniswiseman]

The fact that it was clear doesn't mean a thing, ponds and lakes are clear but when you stir up the bottom it clouds up
I don't think the robot was the problem, the stuff had to be in there to start, it just got stirred up
Don't start adding anything untill you know what numbers are
How do you test your water, you need to have accurate testing to get your water in balance (Taylor K2006C or TF100)
If you have a sand filter you can add some DE (Diatomaceous Earth) to help filter out the finer particles

[supersub]

Thanks, Dennis!