Hi there, I have no idea if I'm writing this in the right place. A friend of mine owns a bi-orb 30 litre tank which I believe is freshwater. Recently her fish died in unusual and tragic circumstances and I want to buy her some replacements. Unfortunately I have no knowledge or experience of the art of fish keeping. I was looking at finding some characterful invertebrates such as shrimp or crabs as well as some good looking fish. Unfortunately I'm worried about which can interact with each other and whether the tank will be the right size / right type of water. I'd be very appreciative if someone could give me some advice here.
Thanks