I have recently brought a 12 litre tank to sit in my bedroom. I currently have black sand, thermometer, API tap water conditioner, and a marimo in there with a air pump to power a sponge filter that is on the way. I plan to get a 25w heater, it would be more for the winter as the water is holding at 21c for the moment. I also plan to get a API master kit at some point but that might take a while. I plan to stock the tank with 5 red cherry shrimp and to let them breed to the size of the tank. For feeding, I was planning on using algea wafers and veg. For calcium supplements, I'll use some cuttlebone or perhaps the snail jelly if I can the English equivalent ingredient. I was also wondering if I could add a horned nerite snail or a few thai micro crabs. I won't if the bioload is too much or if there isn't enough room. Any advice and tips would be greatly appreciated. Thanks.