I am a beginner from India. I have a 10 gallons aquarium with two small starfish, one slug. Whenever I add fishes, one or two, they keep dying after about 5 days since adding. I'm not sure why they keep dying as I feel my bio media, rocks and sand lil ceramic blocks should be fine. But still the fishes keeps dying after 4-5 days of adding. I'm going pretty much hopeless and clueless as to why this is happening so looking for help from the community. Thanks