Stocking a 20 gallon aquarium

The data behind this page

The Fishkeeping Network

Stocking guidelines: which species fit a tank, the group sizes they need, and the warnings that come with them.

The Aquarium Wiki (theaquariumwiki.com)

Water chemistry requirements: the pH, hardness and temperature each species is kept in.

Used under CC BY-SA 3.0.

Tank size

11 L 19 L 38 L 75 L 110 L 150 L 208 L 280 L 473 L 680 L

Your water (optional)

Your temperature

°C

Your hardness

dGH

Your pH

Your plan

Add fish with the “+ Add” buttons below to see if they will work together in your tank.

20 Gallon / 75 Liter

Commonly available onlyHide brackish

34 groups fit

Assumes the standard 76 × 30 cm footprint. Dimensions matter more than volume, so if your tank is shorter, enter its dimensions above.

Fish

African Cichlids Shell Dwellers

5 species

Boulengeri(Lepidiolamprologus boulengeri)75 L · 76 cm
Pairs or Harem
~23–27°C · ~8–12 dGH · ~pH 7.4–8.4
Multis(Neolamprologus multifasciatus)COMMON75 L · 76 cm
Group
24–28°C · 12–20 dGH · pH 7.8–8.5
Signatus(Lamprologus signatus)75 L · 76 cm
Pairs or Harem
25–28°C · 9–19 dGH · pH 7.5–8
Similis(Neolamprologus similis)COMMON75 L · 76 cm
Pairs or Harem
~24–26°C · ~9–18 dGH · ~pH 7.8–8.5
Stappersii(Lamprologus stappersi)75 L · 76 cm
Pairs or Harem
23–27°C · 8–25 dGH · pH 7.5–9

Badis

2 species

Scarlet(Dario dario)COMMON19 L · 40 cm
Solitary male
22–26°C · 5–15 dGH · pH 6.5–7.5
Blue(Badis badis)38 L · 50 cm
Solitary male
23–26°C · 5–19 dGH · pH 6–8

Group in a 20 gallon tank or larger

Initially require live food

Barbs

14 species

Dwarf Ember(Barboides gracilis)38 L · 50 cm
School 8+
21–26°C · 0–6 dGH · pH 6–7
Bandula(Pethia bandula)75 L · 76 cm
School 8+
~22–26°C · ~5–12 dGH · ~pH 6.5–7.2
Black Ruby(Pethia nigrofasciatus)75 L · 76 cm
School 8+
22–26°C · 6–10 dGH · pH 6–7
Butterfly(Barbus hulstaerti)75 L · 76 cm
School 8+
22–24°C · 5–10 dGH · pH 5–6.5
Checkered(Oliotius oligolepis)75 L · 76 cm
School 8+
22–27°C · 4–10 dGH · pH 6.5–7.2
Cherry(Puntius titteya)COMMON75 L · 76 cm
School 8+
22–27°C · 6–10 dGH · pH 6.5–7

Betta

18 species

Longfin Splendens(Betta splendens)COMMON19 L · 40 cm
Solitary
24–28°C · 4–10 dGH · pH 6–7.8
Longfin (and Shortfin) splendens genetics are severely damaged
Albimarginata(Betta albimarginata)38 L · 50 cm
Solitary
21–28°C · 4–10 dGH · pH 5.5–7
Anabatoides(Betta anabatoides)38 L · 50 cm
Solitary
27–30°C · 1–5 dGH · pH 4.5–7.5
Coccina(Betta coccina)38 L · 50 cm
Solitary
24–28°C · 0–6 dGH · pH 4–6
Dimidiata(Betta dimidiata)38 L · 50 cm
Solitary
~24–28°C · ~2–10 dGH · ~pH 5.5–7
Edithae(Betta edithae)38 L · 50 cm
Solitary
~24–28°C · ~2–10 dGH · ~pH 5.5–7

Potentially community compatible in larger tanks
Rubra & Dennisyongi Solitary or Group

Compatible with Snails & Clams, Potentially Compatible with Shrimp, incompatible with fish

Catfish

4 species

Dwarf Anchor/Asian Stone(Hara jerdoni)COMMON38 L · 50 cm
Shoal 6+
20–24°C · 8–12 dGH · pH 6.7–7.2
Bumblebee(Batrochoglanis raninus)75 L · 76 cm
Solitary, Groups
21–25°C · 8–10 dGH · pH 6–7
False Cuckoo Synodontis/Pygmy Leopard(Synodontis petricola)75 L · 76 cm
Solitary, Groups
~22–26°C · ~6–19 dGH · ~pH 6.4–8
Honeycomb(Centromochlus perugiae)75 L · 76 cm
Solitary, Groups
24–28°C · 6–10 dGH · pH 6.5–7.2

Corydoras

62 species

Cochui(Corydoras cochui)38 L · 50 cm
Shoal 6+
~22–26°C · ~2–12 dGH · ~pH 6–7.2
Gracilis38 L · 50 cm
Shoal 6+
~22–26°C · ~2–12 dGH · ~pH 6–7.2
Polystictus(Corydoras polystictus)38 L · 50 cm
Shoal 6+
20–25°C · 2–18 dGH · pH 6–7.6
Pygmy(Corydoras pygmaeus)COMMON38 L · 50 cm
Shoal 6+
22–26°C · 6–16 dGH · pH 6–8
Salt & Pepper/Habrosus(Corydoras habrosus)COMMON38 L · 50 cm
Shoal 6+
22–26°C · 8–15 dGH · pH 6.2–7.2
Sixray(Aspidoras pauciradiatus)38 L · 50 cm
Shoal 6+
22–25°C · 3–12 dGH · pH 6–7.2

Heavily prefer sand

Danios

17 species

Ethereal(Danionella cerebrum)19 L · 40 cm
Shoal 6+
~20–25°C · ~5–12 dGH · ~pH 6.5–7.5
Celestial Pearl(Danio margaritatus)COMMON38 L · 50 cm
Shoal 6+
20–26°C · 8–12 dGH · pH 5.7–8
Blue(Danio kerri)75 L · 76 cm
Shoal 6+
23–25°C · 6–16 dGH · pH 6.5–7
Dwarf Spotted(Danio nigrofasciatus)75 L · 76 cm
Shoal 6+
24–28°C · 5–12 dGH · pH 6.5–7
Emerald Dwarf(Danio erythromicron)COMMON75 L · 76 cm
Shoal 6+
21–25°C · 10–25 dGH · pH 7–7.5
Firebar(Devario maetaengensis)75 L · 76 cm
Shoal 6+
20–25°C · 1–5 dGH · pH 6–7.2

Gobies

14 species

Annie's(Stiphodon annieae)38 L · 50 cm
Harem
~23–28°C · ~5–12 dGH · ~pH 6.5–8
Lumbantobing(Pseudogobiopsis lumbantobing)38 L · 50 cm
Group 3+
~22–26°C · ~6–14 dGH · ~pH 6.5–7.5
Red Spotted(Rhinogobius rubromaculatus)38 L · 50 cm
Pair
~15–25°C · ~6–16 dGH · ~pH 7.5–8
Rhino Horn(Redigobius balteatus)38 L · 50 cm
Group 3+
~22–26°C · ~6–14 dGH · ~pH 7–8
Tiger Dwarf(Mugilogobius tigrinus)BRACKISH38 L · 50 cm
Group 3+
~22–26°C · ~6–14 dGH · ~pH 7.2–8.2
True Freshwater Bumblebee(Brachygobius xanthomelas)38 L · 50 cm
Group 3+
~22–29°C · ~8–12 dGH · ~pH 8–8.2

Males territorial but not aggressive.

Gourami

9 species

Dwarf/Powder Blue(Trichogaster lalius)COMMON38 L · 50 cm
Solitary or Harem
22–28°C · 4–13 dGH · pH 6.5–7.5
Very susceptible to iridovirus
Common strains have extremely compromised genetics due to inbreeding, so they aren't advisable unless sourced with extreme discretion
Honey(Colisa chuna)COMMON38 L · 50 cm
Solitary Honey Gourami or Red Robin Gourami can fit in Fluval Flex 15
22–26°C · 6–10 dGH · pH 6.5–7.5
Often confused with Thick Lipped
Common strains have extremely compromised genetics due to inbreeding, so they aren't advisable unless sourced with extreme discretion
Red Robin(Trichogaster chuna)38 L · 50 cm
Solitary Honey Gourami or Red Robin Gourami can fit in Fluval Flex 15
22–26°C · 6–10 dGH · pH 6.5–7.5
Often confused with Thick Lipped
Congo Ctenopoma75 L · 76 cm
Pair
~24–28°C · ~5–19 dGH · ~pH 6–7.5
Dwarf Ctenopoma75 L · 76 cm
Pair
~24–28°C · ~5–19 dGH · ~pH 6–7.5
Licorice(Parosphromenus deissneri)75 L · 76 cm
Group
23–28°C · 0–2 dGH · pH 3–7

Gudgeon

1 species

Peacock(Tateurndina ocellicauda)COMMON75 L · 76 cm
Group 6+
23–28°C · 4–14 dGH · pH 6.5–8

Hatchetfish

7 species

Black-Winged(Carnegiella marthae)75 L · 76 cm
School 8+
24–29°C · 1–8 dGH · pH 5.5–7
Common(Gasteropelecus sternicla)75 L · 76 cm
School 8+
23–27°C · 10–15 dGH · pH 6–7
Marble(Carnegiella strigata)75 L · 76 cm
School 8+
24–29°C · 5–18 dGH · pH 5–7.5
Marbled(Carnegiella strigata)COMMON75 L · 76 cm
School 8+
24–29°C · 5–18 dGH · pH 5–7.5
Pygmy(Carnegiella myersi)75 L · 76 cm
School 8+
23–26°C · 10–20 dGH · pH 5.5–6.5
Silver(Gasteropelecus sternicla)COMMON75 L · 76 cm
School 8+
23–27°C · 10–15 dGH · pH 6–7

Hatchetfish jump

Indostomus

1 species

Paradox Fish/Armored Stickleback/Toothpick Fish(Indostomus paradoxus)19 L · 40 cm
Trio
24–28°C · 6–10 dGH · pH 6.5–7.5

Require live food
Require a very heavily planted tank

Killifish

10 species

Bluefin Notho(Nothobranchius rachovii)NothobranchiusCOMMON19 L · 40 cm
Least Shoaling (6+)
20–24°C · 3–10 dGH · pH 6–7
Egger's(Nothobranchius eggersi)Nothobranchius19 L · 40 cm
Least Shoaling (6+)
24–28°C · 10–25 dGH · pH 7–8.2
Foerschi(Nothobranchius foerschi)Nothobranchius19 L · 40 cm
Least Shoaling (6+)
22–26°C · 10–25 dGH · pH 6.5–7.5
Gunther's(Nothobranchius guentheri)Nothobranchius19 L · 40 cm
Least Shoaling (6+)
22–25°C · 5–20 dGH · pH 7–8
KisakiNothobranchius19 L · 40 cm
Least Shoaling (6+)
~22–27°C · ~10–25 dGH · ~pH 6.75–7.75
Korthausae(Nothobranchius korthausae)Nothobranchius19 L · 40 cm
Least Shoaling (6+)
~22–27°C · ~10–25 dGH · ~pH 6.75–7.75

Nothobranchius Pairs (Trio or Small Harem in a 10 gallon tank or larger, Large Harem in a 20 long tank)

Killifish Aphyosemion

16 species

Australe/Lyretail(Aphyosemion australe)75 L · 76 cm
Shoal 6+
22–25°C · 5–12 dGH · pH 5.5–6.5
Banded Topminnow(Fundulus cingulatus)COMMON75 L · 76 cm
Solitary or Groups (3+)
~15–25°C · ~5–12 dGH · ~pH 6.5–7.5
Blue-Striped Rivulus(Laimosemion xiphidius)75 L · 76 cm
Shoal 6+
~22–25°C · ~5–14 dGH · ~pH 6–7
Bluefin(Lucania goodei)75 L · 76 cm
Shoal 6+
10–28°C · 3–15 dGH · pH 6.5–8
Chevalier's(Epiplatys chevalieri)75 L · 76 cm
Shoal 6+
~22–24°C · ~5–11 dGH · ~pH 6–7
Christy's(Aphyosemion christyi)75 L · 76 cm
Shoal 6+
~20–24°C · ~4–12 dGH · ~pH 6–7

Livebearers

26 species

Least Killifish(Heterandria formosa)COMMON19 L · 40 cm
Shoal 6+
16–24°C · 5–20 dGH · pH 7–8
Not killifish, they are livebearers
Tiger Teddy(Neoheterandria elegans)19 L · 40 cm
Shoal 6+
~23–28°C · ~pH 7–8
Bifurca Guppy(Micropoecilia bifurca)38 L · 50 cm
Shoal 6+
~23–28°C · ~pH 7–8
Blackstripe Porthole(Poeciliopsis prolifica)38 L · 50 cm
Shoal 6+
~23–28°C · ~pH 7–8
Branneri Guppy(Micropoecilia branneri)38 L · 50 cm
Shoal 6+
~23–28°C · ~pH 6.3–7.3
Dusky Millions(Phalloceros caudimaculatus)38 L · 50 cm
Shoal 6+
25–28°C · 9–19 dGH · pH 7–8

Guppies Males Only

Loach

17 species

Banded Hillstream(Pseudogastromyzon changtingensis)75 L · 76 cm
Shoal 6+
~23–28°C · ~6–12 dGH · ~pH 6.3–7.3
Black Kuhli(Pangio kuhlii)75 L · 76 cm
Shoal 6+
24–28°C · 1–13 dGH · pH 5.5–7.5
Borneo(Pangio shelfordii)COMMON75 L · 76 cm
Shoal 6+
~24–26°C · ~6–13 dGH · ~pH 6.25–7.5
Chain(Yasuhikotakia sidthimunki)COMMON75 L · 76 cm
Shoal 6+
26–28°C · 6–20 dGH · pH 6.5–8
Cow River(Neogastromyzon crassiobex)75 L · 76 cm
Shoal 6+
~23–28°C · ~6–12 dGH · ~pH 7–8
Deze Chinese(Sinogastromyzon dezeensis)75 L · 76 cm
Shoal 6+
~23–28°C · ~6–12 dGH · ~pH 6.5–7.5

All hillstream except Butterfly/Reticulated/Tiger require high flow

Minnows

4 species

Garnet(Aphyocypris lini)75 L · 76 cm
School 8+
~7–18 dGH · ~pH 7.5–8.5
Highfin(Notropis altipinnis)Shiners75 L · 76 cm
School 8+
~7–18 dGH · ~pH 7–8
Vietnamese(Tanichthys micagemmae)75 L · 76 cm
School 8+
18–23°C · 6–16 dGH · pH 6.5–7.2
White Cloud(Tanichthys albonubes)COMMON75 L · 76 cm
School 8+
10–23°C · 5–19 dGH · pH 6–8

Minnows need cold, fast water

North American Cichilds

2 species

Banded Sunfish(Enneacanthus obesus)75 L · 76 cm
Solitary or Pair
~7–22°C · ~8–12 dGH · ~pH 6.75–7.5
Spotted Sunfish(Lepomis punctatus)75 L · 76 cm
Solitary or Pair
~4–22°C · ~10–15 dGH · ~pH 7–7.5

Require species-only or North American-only tank

Otocinclus

5 species

Bumblebee38 L · 50 cm
Shoal 6+
~21–26°C · ~8–20 dGH · ~pH 6–8
Common(Otocinclus vittatus)COMMON38 L · 50 cm
Shoal 6+
21–26°C · 6–10 dGH · pH 5.5–7.5
Haroldoi/Dwarf Pleco38 L · 50 cm
Shoal 6+
~21–26°C · ~8–20 dGH · ~pH 6–8
Not Plecostomus, they are a species of Otocinclus
Robocop38 L · 50 cm
Shoal 6+
~21–26°C · ~8–20 dGH · ~pH 6–8
Tiger(Otocinclus cocama)38 L · 50 cm
Shoal 6+
21–24°C · 8–12 dGH · pH 6–7.5

Most Otocinclus are purchased with dead gut bacteria.
Require a mature tank (1 Year +) OR 24/7 powdered food access + BacterAE

Pencilfish

9 species

Miniature(Nannostomus anduzei)38 L · 50 cm
School 8+
~24–28°C · ~4–8 dGH · ~pH 5.5–7
Barred(Nannostomus espei)75 L · 76 cm
School 8+
22–26°C · 4–10 dGH · pH 5.5–7
Coral Red(Nannostomus mortenthaleri)COMMON75 L · 76 cm
School 8+
24–28°C · 2–10 dGH · pH 5.8–7
Dwarf(Nannostomus marginatus)75 L · 76 cm
School 8+
24–26°C · 10–15 dGH · pH 6.8–7.5
Golden/Beckford(Nannostomus beckfordi)COMMON75 L · 76 cm
School 8+
24–26°C · 5–19 dGH · pH 6–8
Purple(Nannostomus rubrocaudatus)75 L · 76 cm
School 8+
~24–28°C · ~4–8 dGH · ~pH 5.5–7

Pufferfish

4 species

Irrubesco(Carinotetraodon irrubesco)75 L · 76 cm
Solitary; Harem in a 40 gallon tank or larger
23–26°C · 8–15 dGH · pH 6–7.8
Ocellated(Leiodon cutcutia)75 L · 76 cm
Solitary
23–27°C · 5–12 dGH · pH 6–7.8
Aggressive
Pea(Carinotetraodon travancoricus)COMMON75 L · 76 cm
Pea Solitary or Groups
24–26°C · 5–10 dGH · pH 7–8.5
Pea species only
Striped Redeye(Carinotetraodon salivator)75 L · 76 cm
Solitary; Harem in a 40 gallon tank or larger
23–27°C · 5–12 dGH · pH 6–7.8

Congo/Potato Require Sand

Pygmy Sunfish

7 species

Alabamae(Elassoma alabamae)11 L · 22 cm
Solitary
~10–25°C · ~6–16 dGH · ~pH 6–7.5
Boehlkei(Elassoma boehlkei)11 L · 22 cm
Solitary
10–25°C · 6–16 dGH · pH 5.5–7.2
Evergladei(Elassoma evergladei)11 L · 22 cm
Solitary
10–30°C · 3–15 dGH · pH 6–8
Gilberti(Elassoma gilberti)11 L · 22 cm
Solitary
15–24°C · 5–12 dGH · pH 6.5–7.5
Okatie(Elassoma okatie)11 L · 22 cm
Solitary
10–23°C · 6–16 dGH · pH 6.5–7.5
Okefenokee(Elassoma okefenokee)11 L · 22 cm
Solitary
4–30°C · 6–20 dGH · pH 6–8

Colonies permissible in extremely dense tanks

Require Live Food
Require a very heavily planted tank

Rainbowfish

11 species

Furcata(Pseudomugil furcatus)COMMON75 L · 76 cm
School 6+
24–27°C · 5–12 dGH · pH 6.5–8
Honey Blue-Eye(Pseudomugil mellis)75 L · 76 cm
School 6+
24–28°C · 5–12 dGH · pH 6–8
Ivanstoff(Pseudomugil ivantsoffi)75 L · 76 cm
School 6+
~24–28°C · ~5–12 dGH · ~pH 6.5–7.9
Luminatus/Red Neon Blue Eye(Pseudomugil luminatus)75 L · 76 cm
School 6+
~24–28°C · ~5–12 dGH · ~pH 6.5–7.9
Neon Blue Eye(Pseudomugil cyanodorsalis)BRACKISH75 L · 76 cm
School 6+
~24–28°C · ~5–12 dGH · ~pH 6.5–7.9
Popondetta Blue-Eye(Pseudomugil connieae)75 L · 76 cm
School 6+
24–27°C · 8–15 dGH · pH 7.7–7.9

Rasboras

16 species

Chili(Boraras brigittae)COMMON38 L · 50 cm
School 8+
25–28°C · 8–10 dGH · pH 6.5–7
Galaxy(Danio margaritatus)COMMON38 L · 50 cm
School 8+
20–26°C · 8–12 dGH · pH 5.7–8
Neon Blue(Sundadanio axelrodi)COMMON38 L · 50 cm
School 8+
23–26°C · 2–10 dGH · pH 6–6.5
Neon Green(Microdevario kubotai)COMMON38 L · 50 cm
School 8+
20–27°C · 8–10 dGH · pH 6–7
Neon Red(Sundadanio rubellus)COMMON38 L · 50 cm
School 8+
~23–26°C · ~6–12 dGH · ~pH 5–6
Phoenix(Boraras merah)COMMON38 L · 50 cm
School 8+
25–28°C · 8–10 dGH · pH 6.5–7

Ricefish

6 species

Daisy's(Oryzias woworae)38 L · 50 cm
Shoal 6+
24–27°C · 5–12 dGH · pH 6.5–7.5
Indian Blue(Oryzias dancena)38 L · 50 cm
Shoal 6+
~23–26°C · ~7–14 dGH · ~pH 7–7.75
Javanese(Oryzias javanicus)38 L · 50 cm
Shoal 6+
~23–26°C · ~7–14 dGH · ~pH 7–7.75
Pectoral Spot(Oryzias pectoralis)38 L · 50 cm
Shoal 6+
~23–26°C · ~7–14 dGH · ~pH 7–7.75
Celebes(Oryzias celebensis)75 L · 76 cm
Shoal 6+
22–30°C · 10–16 dGH · pH 8–9
Platinum Medaka(Oryzias latipes)COMMON75 L · 76 cm
Shoal 6+
18–24°C · 9–19 dGH · pH 7–8

Snakehead

1 species

Andrao(Channa andrao)COMMON75 L · 76 cm
Solitary
~22–27°C · ~8–16 dGH · ~pH 6.5–7.5

Pair in a 55 gallon tank or larger

Illegal in the U.S. and Canada
Very Aggressive

South American Cichlids

12 species

Barlow's(Apistogramma barlowi)Apistogramma75 L · 76 cm
Solitary or Pair
~24–28°C · ~2–6 dGH · ~pH 5.65–7
Blue CheekApistogramma75 L · 76 cm
Solitary or Pair
~24–28°C · ~2–6 dGH · ~pH 5.65–7
Bolivian Ram(Mikrogeophagus altispinosus)COMMON75 L · 76 cm
Solitary or Pair
24–27°C · 5–10 dGH · pH 6–7
Borellii(Apistogramma borellii)Apistogramma75 L · 76 cm
Solitary or Pair
10–27°C · 3–12 dGH · pH 6–8
Dwarf Flag/Smiling Acara(Laetacara curviceps)75 L · 76 cm
Group 5+
22–26°C · 5–12 dGH · pH 5.2–7.5
Elizabeth's(Apistogramma elizabethae)Apistogramma75 L · 76 cm
Solitary or Pair
~24–28°C · ~2–6 dGH · ~pH 5.65–7

Ram & Apistogramma** can be kept Solitary Non-Community in a 10 gallon tank or larger
**Only Apistogramma species in this column

Female Apistogramma are aggressive

Tetras

50 species

Adonis(Lepidarchus adonis)38 L · 50 cm
School 8+
22–26°C · 4–8 dGH · pH 5.8–6.5
Dwarf Blue(Tyttocharax cochui)38 L · 50 cm
School 8+
~23–27°C · ~5–12 dGH · ~pH 6–7
Ember(Hyphessobrycon amandae)COMMON38 L · 50 cm
School 8+
24–28°C · 6–10 dGH · pH 6.5–7
Gold Neon(Paracheirodon innesi)38 L · 50 cm
School 8+
22–26°C · 4–10 dGH · pH 4.6–7.6
Green Neon(Paracheirodon simulans)COMMON38 L · 50 cm
School 8+
23–27°C · 4–6 dGH · pH 5.5–6
Hummingbird(Characidium rachovii)38 L · 50 cm
School 8+
20–24°C · 10–25 dGH · pH 5.6–7.5

Invertebrates

Clams/Mussels

1 species

Clams/Mussels(Anodonta anatina)11 L · 22 cm
Solitary or Groups
22–28°C · 8–10 dGH · pH 6.5–8

Crabs

7 species

Pom Pom(Ptychognathus barbatus)11 L · 22 cm
Solitary or Groups
~22–27°C · ~8–12 dGH · ~pH 6.5–7.5
Very difficult to keep
Thai Micro(Limnopilos naiyanetri)COMMON11 L · 22 cm
Solitary or Groups
22–26°C · 8–12 dGH · pH 7.2–8
Blue Legged Hermit(Clibanarius tricolor)COMMONBRACKISH19 L · 40 cm
Solitary; Groups
22–26°C · 8–12 dGH · pH 8.1–8.4
Ghost Dwarf19 L · 40 cm
Solitary; Groups
~22–27°C · ~8–12 dGH · ~pH 7–8
Panther(Parathelphusa pantherina)COMMON75 L · 76 cm
Solitary
~22–27°C · ~8–12 dGH · ~pH 7–8
Thinstripe Hermit(Clibanarius vittatus)BRACKISH75 L · 76 cm
Solitary
~22–27°C · ~8–12 dGH · ~pH 7.5–8.3

Crayfish

3 species

Amano(Caridina multidentata)ShrimpCOMMON38 L · 50 cm
Group
18–27°C · 6–10 dGH · pH 6–7.5
Need brackish to breed
Cambarellus(Cambarellus patzcuarensis)38 L · 50 cm
Solitary, Pair
22–24°C · 12–14 dGH · pH 7.5–8
Dwarf Orange/Mexican(Cambarellus patzcuarensis)COMMON38 L · 50 cm
Solitary, Pair
22–24°C · 12–14 dGH · pH 7.5–8

Group in a 15g/20h tank

Crayfish aggression is based on individual personality
Crayfish illegal in UK

Scuds

1 species

Scuds(Hyalella azteca)11 L · 22 cm
Group
10–26°C · 8–18 dGH · pH 6.5–8.5

Can be kept in smaller tanks

Shrimp

13 species

Amazon Zebra(Euryrhynchus amazoniensis)11 L · 22 cm
Group
~3–10 dGH · ~pH 5–6
Caridina(Caridina multidentata)COMMON11 L · 22 cm
Group
18–27°C · 6–10 dGH · pH 6–7.5
Fairy11 L · 22 cm
Group
~3–10 dGH · ~pH 7–8
Fairy Shrimp can be kept in Smaller Tanks
Ghost(Palaemonetes paludosus)COMMON11 L · 22 cm
Group
20–29°C · 3–10 dGH · pH 7–8
Halocaridina/Opae Ula(Halocaridina rubra)BRACKISH11 L · 22 cm
Group
22–28°C · 2–15 dGH · pH 7.5–8
Neocaridina/Cherry(Neocaridina heteropoda)COMMON11 L · 22 cm
Group
22–28°C · 8–12 dGH · pH 6.4–8.4

Snails

25 species

Assassin(Anentome helena)COMMON11 L · 22 cm
Solitary or Groups
23–27°C · 8–15 dGH · pH 7.2–8
Actively eat other snails, eggs, and recently molted invertebrates
Bladder(Physa acuta)COMMON11 L · 22 cm
Solitary or Groups
18–25°C · 6–12 dGH · pH 7.2–8.5
Hairy(Thiara cancellata)11 L · 22 cm
Solitary or Groups
22–26°C · 8–15 dGH · ~pH 7–8
Limpet Nerite(Septaria porcellana)11 L · 22 cm
Solitary or Groups
23–28°C · 8–15 dGH · ~pH 7–8
Malaysian Trumpet(Melanoides tuberculata)COMMON11 L · 22 cm
Solitary or Groups
18–30°C · 6–15 dGH · pH 7–8
Mud11 L · 22 cm
Solitary or Groups
~8–15 dGH · ~pH 7–8

All except Assassin, Limpet Nerite, & Hairy Reproduce Asexually

The stocking planner tells you if your tank plan can work, but it cannot say how hard it will be to maintain.

To figure out what it will actually take to keep your tank healthy long term given your specific tank setup, water type, environment, etc. you can run your tank through the simulator.