These Turbo castanea snails are great little algae eaters and are usually more colorful than the astrea snail. The main colors we get are orangish color or grey-green. Sometimes they even have pinks or purples in the shell too. The ones that we get are around 0.25 to 0.5 inches from top to bottom of the shell. They are considered reef safe and their primary diet is algae. They will not eat sponges or coral. They are very hardy so are perfect for a beginner (although the experts love them too). They seem to be somewhat seasonal so get them before the season is over.