HG Headstone Cleaner Spray - 500ml

I cannot believe how effective this spray is. My grandparents' headstone had been largely untouched for 50 years and the white marble was virtually dark brown. With one bottle of spray, two gallons of water and a portable jet washer I returned this headstone to brilliant white and looking almost new in a little over one hour.
The effect is breath-taking and I cannot recommend this cleaner spray highly enough.

It says it on the bottle. Used it before on marble gravestone. As instructed don't leave it on for more than a couple of minutes on marble. Do it again if need to. Leave it up to 20-30 minutes on other stones. Removes not just green algae but black marks from fungus. One bottle will cover 2-3 cleans. Very happy with results compared to just soapy water. Recommend.