Will these fish fit, and get along?

One betta, or a school of 6 to 8 nano fish such as ember tetras or chili rasboras, plus a few shrimp or a snail. Goldfish, angelfish and most plecos need much bigger tanks.

Only roughly. A thick-bodied 4 inch fish makes far more waste than four 1 inch tetras, so TankCoach weighs each species' bioload and the filter's flow.

Only to a cycled tank, a few at a time, about a week apart, testing ammonia and nitrite in between.