I cannot seem to control a string algae problem. I add beneficial bacteria weekly and use your algaecide product, but I’m having no luck. Is this a Ph in the water problem and is there a way to prevent this algae rather than treat it after it appears? Right now I’m forced to powerwash everything every couple weeks.

String algae problems mean you have too many nutrients in the pond and not enough plants.
Look into the IonGen which is a electronic device that release metal ions into the water to control the string algae and it is safe for the fish. Also, you may need to clean out the pond as everything that sinks to the bottom of the pond will have to decompose and will cause an algae bloom. Chemical treatments are difficult and hard on the fish and your pond becomes dependent on them. Also the EcoBlast works well on the rocks of the waterfall and stream. Watch the DIY video on the IonGen.