Can Guppy Live With Green swordtail?

Detailed assessment

Both Guppy and Green swordtail share a comfortable temperature range of 22–28°C (Guppy prefers 22–28°C, Green swordtail prefers 16–28°C). Their pH ranges overlap well at 7–8, so water chemistry is compatible. Both species have low aggression scores (Guppy: 1, Green swordtail: 1 out of 10), which supports peaceful cohabitation. They occupy different water columns (Guppy: middle, Green swordtail: all), which reduces direct competition for space. The size difference is significant: Green swordtail reaches 16 cm while Guppy reaches only 5 cm, and the larger species may view the smaller one as prey. Note: fish 2x+ larger may eat smaller tankmates With careful monitoring and adequate tank size these species can usually coexist, but be prepared to separate them if aggression or stress appears.