Hi fellow hobbists,

I would like your advice on what is the best way to remove algae from my rock before i can reuse it again?

I found out there is purple algae growing on it . I did a search and found the main methods are to use bleach solution and then boil it, anyone has tried this before and is this safe?

Also can you help me identify if it is a BORNEOWILD IWA KURO-YOUGAN (Black Volanic Rocks)? i bought it from greenchapter but cant remember which type.
Picture as per below. Thanks!