I've been asked to clean a patio for a family member, it is filthy and green with algae as it is sinking down to one corner allowing water to sit. For the time being they want it cleaning and have bought Sodium Hypochlorite. I intend on pressure washing first and applying with a watering can but what ratio do you use?
It is 15% strength. I am doing quite a big area, perhaps 20 feet square. Can anyone tell me how many chemicals to put in and how much water? I struggle with working things out. Am wearing chemical resistant gloves, goggles and a mask, Thank you