How Many Guppys in a 29 Gallon Tank?
About 11–15 — based on adult size, bioload, and real water volume.
About 11–15 guppy
Photo via Wikimedia Commons
In a 29-gallon tank you can comfortably keep about 11–15 guppy — enough for a proper school, on their own with good filtration and regular water changes. Add fewer if you're mixing in other species.
How we get that number
An adult guppy reaches about 2.0" and has a low bioload. Working from real water volume and waste output (not the old one-inch-per-gallon myth), a 29-gallon tank supports roughly 11–15 of them. Because guppy are schooling fish, keep them in a group of at least 3 — never just one or two. They need 72–82°F water at pH 7–8.
Build your exact stocking with the calculator → Full guppy care guide →
Gear for a 29-gallon tank
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FAQ
How many guppy can I keep in a 29 gallon tank?
About 11–15 guppy, kept on their own with good filtration. Add fewer when combining with other species — use the stocking calculator to be sure.