I am a pool owner with moss rock waterfall (actually it's a weeping wall) with boulders submerged below the water line. When gunite was shot, they made a "shelf". Boulders were then stacked and grouted together on one wall instead of placing the waterline tile. Pool is one year old. There is no moss or algae growing on the rock. I have balanced the water appropriately with chlorine and have not had to "clean" rock at all.

thanks for the reply. ours too is considered a weeping waterfall as it will run off the same intelliflo pump as the rest of the pool. good to hear there is no problem with algae buildup. i think it does look better when the rocks are submerged.

You keep that CL, PH, TA, and CYA where they need to be and you will never see algae.

Rocks will form areas of poor circulation and algae will form on occasion. Fortunately, Clorox poured over the area usually takes care of it. You might need to brush it a bit too.

Scott