Algae Control: Home Gardening and Landscaping:

Physan 20 can be used to control algae and other pathogens on inanimate surfaces including bricks, walls, walkways, pots and tools. Mix up a solution of ½ ounce per gallon of water. This solution can be sprayed or applied to walls and walkways to treat and inhibit algae growth. For heavy infestations a repeat application may be needed. The solution can also be used to disinfect gardening tools and pots.