Do I need to hose off copper sulphate on my concrete paths?
Is it applied to wet or dry concrete surfaces ?? broomed in ??
The Bluestone Copper Sulphate is dissolved in a 9 litre watering can and applied to the path where the algae is growing. Leave it to dry on the path to lift the algae and then you can simply broom it off.
Answered: 28 Feb, 2019