algaee - other way round

[superalgae]

Hi there,

Since four years I´m maintaining my pool, and I managed it quite well,
and it was almost perfectly clean and blue until last week:

At this time I wanted to get rid of the algaees once for all, growing on the walls, to be scrubbed off once a week with the broom.

So I added Soda-Ash, only a bit (?!) too much:

3000 g for 32.000 litres!

The pool is nice and clear now, only it has a different colour....dark green!

I would be very happy, if somebody could advise me, what to do:

1> wait 2 weeks and see
2> drain the water and refill the pool (maybe cheapest?)
3> add dry acid (how much?)
4> something else

Thank you all very much for your awaited advice.

Regards

Gerry

P.S.: pH-readings and ppms are not on the scale anymore!