diesel

Recently and after almost as long as I have owned this aquarium, around 1.5 years of siphoning out this green mat (I assume cyano) off from rock and corals, I finally decided to take out all the old rock from my tank and replaced it with live rock I had curing for the last 6 months in a brute...

So I have learned something new since being on r2r recently. That I might have spirulina? Which I thought was blue green cyano. Its on my sand bed. It makes the sand hard in patches. I have had it a while now and I usually syphon some out during water changes. How can I defeat it? I have never...