i have a filter and a pump and a fountain and also i use a type of algae reducer thing (like a syrup) , also there is a shade cloth over the pond. How can i clean all the rocks that have algae on them, so far i have cleaned abit of them one by one with a sponge, can i put them in boiling water to kill the algae any suggestions??????? thankkyouu (10 points best answer)

There is a pump with a fountain. I think I am missing parts but don’t know what to order as I don’t understand the workings of the 2 tier pond. I don’t know how to pump the water back to the top tier so it can flow over the rocks to the bottom. The tubing seems to be cemented in also. Thank You