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Destiny
Hello, dear aquarium enthusiasts! Please advise. I have started setting up a marine aquarium. I filled the aquarium with water, added coral gravel, and salted the water. After that, I added live sand, and exactly two days later, a reddish-brown coating appeared in some places on the sand! The salt level is normal, unfortunately I haven't done any tests yet! I also don't have any live rock yet. Can you please tell me what this is and if it's dangerous? I don't have any experience with marine aquariums yet. Any