Can Guppy Live With Neon tetra?

Temperament is not the issue with this pair. Guppies are very peaceful and do well in a quiet community that includes tetras, and the neon is a generally peaceful fish that suits a well-planned community.

The water is where they part ways. Guppies need pH 7 to 8, while neons show their best colour in soft, acidic water and take pH 4 to 7.5. The shared ground is pH 7 to 7.5 at 21 to 25 °C. That puts the neons at the top of their pH range and the guppies at the bottom of theirs, and it caps the temperature well below the guppy's 28 °C.

If your tap water sits around neutral, the pairing can work. Keep 8 to 10 neons or more so the school settles, in a tank with a base of at least 60 by 30 cm, and keep one male guppy to at least two females so the males do not harass the females constantly. The neons hold the middle of the tank and the guppies stay near the surface, so the two groups do not crowd each other.