other

Hey, I’m new to the forum and aquarium hobby. Me and my family are trying to get a saltwater aquarium, and was I wondering if things like clown fish, hermit crabs porcelain crabs, and others could be kept with a mandarin dragonet.

Please can you help me ID these, they are teeny and on the back of a hermit shell so easy to remove if a pest. they are however actually quite pretty and fluoresce under the lights at the edge of the oral plate. Thanks in advance!!

Are these diatoms still or could they be something different, or are diatoms dying and reforming? I'm confused. I'm at about.the 1 month, 1 week mark since putting biospira and first fish in. Some of this algae is Dark brown, some very light brown. Some rust colored (a yellowish rust) like...