A Blue Head Mosaic Guppy pair (or trio) makes for a stunning, active addition to a peaceful community tank. To keep them healthy, a minimum 10-gallon tank is recommended, though a 20-gallon tank allows more room for fry and swimming. For the best results, use a 1:2 or 1:3 male-to-female ratio to reduce harassment, as males are highly active breeders. 

Tank Setup

Temperature & Parameters: Maintain temperatures between 72°F and 78°F, with a pH of 7.0 to 8.0.

Filtration: Use gentle filtration, such as a sponge filter, to prevent the delicate fins of the mosaic strain from being damaged and to keep tiny fry safe.

Plants & Hiding Spots: Dense live plants (e.g., Java moss, Java fern, Guppy grass) are essential. They provide hiding spots for fry, reducing predation from adults.

Substrate: Smooth gravel or sand works best, covering 1-2 inches of the bottom. 

Compatible Tank Mates

Because of their long, flowing fins, avoid aggressive fish or fin-nippers. Excellent tank mates include: 

Small Schooling Fish: Neon Tetras, Harlequin Rasboras, or Corydoras catfish (especially Pygmy Corys).

Other Livebearers: Mollies, Platies, or Swordtails are great companions that share similar water requirements.

Cleanup Crew: Shrimp (cherry or Amano) and snails (Nerite or mystery snails) help manage algae. 

Avoid keeping them with high-aggression fish like large cichlids or barbs, and be cautious with bettas, as they may view the mosaic’s flowing fins as threats. Keep the water clean with regular, partial water changes to maintain bright coloration and health.