Freshwater fish adult size and minimum tank footprint
Seriously Fish lists a neon tetra at 1.2 in. standard length with a 24 x 12 in. minimum tank base, a betta at 2.8 in. on an 18 x 12 in. base, an angelfish at 6 in. on a 39 x 16 in. base and an oscar at 14 in. on a 60 x 24 in. base.
Last updated: October 10, 2026.
Built by Jeremy Panasuk.
Lengths are standard length (SL), measured to the base of the tail, so they exclude the tail. Seriously Fish gives a minimum tank base footprint, not gallons, so this table does not convert to gallons. "Not recorded" means the species profile does not list that figure.
The data (15 rows)
Figures as published by Seriously Fish species profile (Quick facts). Sources accessed October 10, 2026. Each row links to the page or document the number was read from.
| Fish | Scientific name | Max length (SL, in / mm) | Minimum tank base (in / cm) | Temp (°F) | pH | Source |
|---|---|---|---|---|---|---|
| Bristlenose pleco | Ancistrus sp. | 5 in / 130 mm | 31 × 12 in / 80 × 30 cm | 77–86 | 6.0–7.0 | Seriously Fish species profile (Quick facts) |
| Oscar | Astronotus ocellatus | 14 in / 350 mm | 60 × 24 in / 150 × 60 cm | 68–82 | 6.0–7.5 | Seriously Fish species profile (Quick facts) |
| Betta | Betta splendens | 2.8 in / 70 mm | 18 × 12 in / 45 × 30 cm | 72–86 | 6.0–8.0 | Seriously Fish species profile (Quick facts) |
| Zebra danio | Danio rerio | 2.0 in / 50 mm | 36 × 12 in / 90 × 30 cm | 64–77 | 6.0–8.0 | Seriously Fish species profile (Quick facts) |
| German blue ram | Mikrogeophagus ramirezi | 1.6 in / 40 mm | 24 × 12 in / 60 × 30 cm | 81–86 | 4.0–7.0 | Seriously Fish species profile (Quick facts) |
| Bronze corydoras | Osteogaster aenea (Corydoras aeneus) | 3.0 in / 75 mm | 31 × 12 in / 80 × 30 cm | 70–81 | 6.0–8.0 | Seriously Fish species profile (Quick facts) |
| Neon tetra | Paracheirodon innesi | 1.2 in / 30 mm | 24 × 12 in / 60 × 30 cm | 70–77 | 4.0–7.5 | Seriously Fish species profile (Quick facts) |
| Guppy | Poecilia reticulata | 2.4 in / 60 mm | 18 × 12 in / 45 × 30 cm | 63–82 | 7.0–8.5 | Seriously Fish species profile (Quick facts) |
| Molly | Poecilia sphenops | 3.1 in / 80 mm | 36 × 12 in / 90 × 30 cm | 70–82 | 7.0–8.5 | Seriously Fish species profile (Quick facts) |
| Angelfish | Pterophyllum scalare | 6 in / 150 mm | 39 × 16 in / 100 × 40 cm | 75–86 | 6.0–7.4 | Seriously Fish species profile (Quick facts) |
| Cherry barb | Puntius titteya | 2.0 in / 50 mm | 24 × 12 in / 60 × 30 cm | 68–81 | 6.0–8.0 | Seriously Fish species profile (Quick facts) |
| Discus | Symphysodon aequifasciatus | 6 in / 140 mm | not recorded | not recorded | not recorded | Seriously Fish species profile (Quick facts) |
| Dwarf gourami | Trichogaster lalius | 3.5 in / 88 mm | not recorded | 72–81 | 6.0–7.5 | Seriously Fish species profile (Quick facts) |
| Harlequin rasbora | Trigonostigma heteromorpha | 1.8 in / 45 mm | 24 × 12 in / 60 × 30 cm | 70–82 | 5.0–7.5 | Seriously Fish species profile (Quick facts) |
| Platy | Xiphophorus maculatus | 2.0 in / 50 mm | 24 × 12 in / 60 × 30 cm | 68–79 | 7.0–8.2 | Seriously Fish species profile (Quick facts) |
Download
Download the CSV (15 rows, updated 2026-10-10). Same rows as the table, plus each row's source URL and access date.
Cite this data
Suggested citation:
Panasuk, J. (2026). Freshwater fish adult size and minimum tank footprint. aquarium-stocking.com. https://aquarium-stocking.com/freshwater-fish-size-and-tank-data.html (accessed YYYY-MM-DD). Underlying figures: Seriously Fish species profiles.
BibTeX:
@misc{panasuk2026aquariumstocking,
author = {Panasuk, Jeremy}, title = {Freshwater fish adult size and minimum tank footprint}, year = {2026},
howpublished = {\url{https://aquarium-stocking.com/freshwater-fish-size-and-tank-data.html}}, note = {Data from Seriously Fish species profiles; accessed YYYY-MM-DD} }
Please cite the original source too. Questions or corrections: jpanasuk@gmail.com.
Sources
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/ancistrus-sp/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/astronotus-ocellatus/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/betta-splendens/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/danio-rerio/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/mikrogeophagus-ramirezi/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/osteogaster-aenea. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/paracheirodon-innesi/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/poecilia-reticulata/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/poecilia-sphenops/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/pterophyllum-scalare/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/puntius-titteya/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/symphysodon-aequifasciatus/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/trichogaster-lalius/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/trigonostigma-heteromorpha/. Accessed October 10, 2026.
- Seriously Fish species profile (Quick facts): https://www.seriouslyfish.com/species/xiphophorus-maculatus/. Accessed October 10, 2026.
License
All rights reserved. Citation and non-commercial reuse are fine with a link back to this page. The underlying figures belong to the original publishers; this page only compiles them.
Use it with the calculator
Run your own numbers on the homepage calculator. How this site handles sources is on the methodology page. Related guides: how many fish per gallon, what size tank for betta fish, what size tank for angelfish, how many fish in a 20 gallon tank.
Compiled with AI assistance from the sources linked above. Spot an error? Email jpanasuk@gmail.com.