I have a 20g fish tank, dimensions are around 18in high, 24in length, 12in wide. Currently it contains 7 neon tetras, a plastic column, and a plastic plant (medium size, about as tall as the tank and around 6 inch diameter base).
I'm looking to get some more creatures for my tank, and have been looking at ghost shrimp. Can I add them? According to this calculator, I'm perfectly fine with a 1:1 ratio of ghost shrimp to neon tetras.
However, is that healthy for both the tetras and ghost shrimp? Should I try to have a 2:1 with more tetras than shrimp, or does it not really matter?