Can Guppy Live With Molly?

Guppies do well in a quiet community with other livebearers, and mollies are peaceful, active livebearers that mix well with similarly sized peaceful company. At 7 to 8 cm a molly is larger than a 5 cm guppy, and it spends much of its day grazing algae and biofilm.

The water suits both. Mollies want hard, alkaline water at pH 7.5 to 8.2, which makes them a poor match for soft-water fish, and guppies take pH 7 to 8. Aim for pH 7.5 to 8 at 24 to 28 °C in a tank of at least 60 litres, the molly's minimum.

Plan for the males. Keep more females than males in both species, at least two female guppies per male, because the males of both court constantly. Both give birth to live young, and in a community tank most of the fry get eaten. Dense planting lets some survive, and in a planted tank the numbers climb fast.