The egglaying Cyprinodonts have always been regarded as difficult because they are believed to require special conditions, namely soft acid water, but while this is true for some species it certainly isn’t the rule for all of them. Many are exceptionally colourful and this alone makes them good aquarium fishes, but to see them at their best requires dedication on the part of the aquarist. It takes a lot of time and patience to maintain banks of small species aquaria, remove eggs from spawning mops, or dry out peat and then raise the fry. For those of us who have kept killifishes the work involved is worth it. If you haven’t very much space, then try with a single species tank.