LFS have one goal... to sell you fish. I have been surprised when they talk about how much they know about saltwater, only to see the puzzled looks on their faces when you ask them something technical. One guy told me saltwater was his specialty. I showed him a vid of my tank, and he named most of the fish. Hmm... maybe he knows his stuff? Then he saw a coral and asked, "What is that?" I told him it was a hammer coral. It's a pretty popular coral, and nothing else looks like a hammer coral, but he didn't have a clue. So close...
There is micro algae, and then there's macro algae. Micro algae is the stuff that coats your glass and rocks. It's the bad stuff. Macro algae is beneficial algae. People use it to compete with micro algae as they both consume the same nutrients. With enough macro algae, you can reduce or eliminate micro algae in the tank. Most macro algae is grown in a refugium, but some people also put in in their main displays. Halimeda, Chaetomorpha, ulva, gracilaria, caulurpa, etc., are types of macro algae. It's the good stuff.
