Algae in rocks?

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
15,866
Tucson, AZ
Looks like moss is having a pleasant time growing in the shade and damp soil near your pool....RoundUp will kill it if you want it too....
 

ajw22

Gold Supporter
TFP Guide
Jul 21, 2013
10,566
Northern NJ
Try Wet & Forget | No Rinse Outdoor Cleaners, Product Selector before you go for stronger stuff.

I use it around the house to kill moss, mold & mildew on stone and siding. I get it at my local Costco. Mix it 5:1 with water in a garden sprayer and spray it on the green areas. Don’t scrub. Let it dry. Give it a few days and the green should disappear. It changes the pH of the area to kill it. Safe for plants and pets.
 

cdingess

Member
Jul 14, 2014
13
Deter, MI
It’s kinda spongy if that sounds right. Would moss be spongy? Also, does that stuff spread in areas with shade? Would more rocks in this area be bad?
Thank you guys so much! I really want this gone before pool opening day.