Cleaning patios

Swooping Swallow

My sandstone patio needs refreshing as it has inevitably built up some algae and is discoloured etc. I have used pressure cleaning before, but I'd rather not do that again as from I read it damages sandstone by opening the stone's pores and making it easier for dirt etc to accumulate. 

Does anyone know of a patio cleaner that is organic, or as close to organic as it's possible for a liquid cleaner to be? I don't want to soak the patio in a liquid that will damage wildlife or plants etc.

Many thanks 

Pete.8

Having been in the same situation as you, I tried this -
https://www.amazon.co.uk/Wet-Forget-Mould-Lichen-Remover/dp/B005IW4GWI

I was skeptical but it has worked surprisingly well
I've used it for 2 consecutive years on the paving around my greenhouse and block paved driveway and have been pleased with the results.
I works quite slowly, but after 2-3 days it just starts to look cleaner and after a week or so there's a big difference

Lizzie27

I've used Algon which is organic I believe (which Patio Magic isn't) and which is half the price of Wet and Forget.