I picked up a NanoCube 28 for free last Friday with stand, supplies and water/creatures that had been running for a year so I figured I couldn't go wrong. There's some hermit crabs, snails, an anemone and a sea urchin. I tested the salinity and used my Nutrafin Saltwater/Freshwater test kit. All the tests came up being ideal for a saltwater tank! I'm unsure about what this green algae is and if it is either good or bad for the tank . Any help would be aopreciated, thank you!