Here's a list of minimum tank sizes for common community and large freshwater fish!(no african cichlids-don't know enough but if you do,please add)
Feel free to add to the list
s=schoolers,need groups of 6 or more
a-aggressive
b=brackish,require marine salt to survive
Fancy Goldfish-20 gallons for one,10 for every after the first
Common Goldfish-55 gallons for one
sRosy Red Minnow-20 gallons
Koi-500 gallons for one,need ponds or huge tanks
aOscar-75 gallons for one
aJack Dempsey-55 gallons for one
Parrot Cichlid-40 gallons
Convict Cichlid-29 gallons
sColombian Tetra-20 gallons
Platy-20 gallons
Guppy-10 gallons
Molly-29 gallons
sUpside Down Catfish-20 gallons
sGlowlight Tetra-20 gallons
sLamp Eye Tetra-20 gallons
sRed Minor Tetra-20 gallons
sVon rio Flame tetra- 20 gallons
sBlack Phantom Tetra-30 gallons
sX ray Tetra- 20 gallons
sMarble Hatchetfish-20 gallons
sSilver Hatchetfish-20 gallons
sMarthae Silver Hatchet-10 gallons
sNeon Tetra-20 gallons
sCardinal Tetra-20 gallons
sGiant Danio-30 gallons
sHarlequin Rasbora-20 gallons
sScissortail Rasbora-20 gallons
sWhite Cloud-20 gallons
sGhost Catfish-30 gallons
sCory-20 gallons
sPygmy Cory-5 gallons
sOtoclinus-10 gallons
Common/Sailfin Pleco-125 gallons
Bristlenose Pleco-20 gallons
Rubber Lip Pleco-30 gallons
sSkirt Tetra-30 gallons
Honey Gourami-20 gallons
Dwarf Gourami-20 gallons
sBuenos Aires Tetra-20 gallons
sBoseami Rainbow-55 gallons
sBloodfin Tetra-20 gallons
sBleeding Heart Tetra-30 gallons
sKhuli Loach-20 gallons
Swordtail-40 gallons
sGlofish-20 gallons
sZebra Danio-20 gallons
sBala Shark-150 gallons
sClown Loach-150 gallons
Pictus Catfish-55 gallons
sRosy Barb-30 gallons
sCherry Barb-20 gallons
sSilver Dollar-125 gallons
sTinfoil Barb-100 gallons
sTiger Barb-30 gallons
Opaline Gourami-30 gallons
Blue Gourami-30 gallons
Betta- 5 gallons
aChinese Algae Eater-55 gallons
aAfrican Brown Knife-100 gallons
aBlack Ghost Knife-125 gallons
Angelfish-30 gallons
aDinosaur Bichir-55 gallons
aRed Tailed Shark-55 gallons
sCelesyial Pearl Danio-5 gallons
sChili Rasbora-5 gallons
Scarlet Badis-5 gallon
Ram-20 gallons
sOdessa Barb-30 gallons
sDension Barb-50 gallons
aOrnate Bichir-75 gallons
sTurqoise Danio-20 gallons
sGlowlight Danio-20 gallons
sDiscus-50 gallons
Redtail Catfish-300 gallons
Silver Arowana-300 gallons
Banded Leporinus-70 gallons
aAfrican Tiger Fish-500 gallons
Pacu-300 gallons
aPiranha-250 gallons
Sparkling Gourami-10 gallons
Pearl Gourami-30 gallons
Blue Paradise Fish-30 gallons
Black Molly-55 gallons
Kissing Gourami-100 gallons
Gold Gourami-30 gallons
Chocolate Gourami-30 gallons
Licorice Gourami-20 gallons
Giant Gourami-100 gallons
Clown Killifish-20 gallons
Gardneri Panchax Killifish-20 gallons
Golden Dream Panchax Killifish-20 gallons
Least Killifish-5 gallons
Striped Raphael Catfish-40 gallon breeder,55 gallons
Reticulated Hillstream Loach-30 gallons
Zebra Pleco-30 gallons
sPraecox Rainbow-20 gallons
sThreadfin Rainbow-10 gallons
Siamese Algae Eater-30 gallons
bColombian Shark-70 gallons
Rainbow Shark-50 gallons
Golden Algae Eater-50 gallons
Whiptail Catfish-50 gallons
sRumynose Tetra-20 gallons
sSilver Tip Tetra-20 gallons
sGreen Fire Tetra-20 gallons
sEmperor Tetra-20 gallons
sHead and Tail Light Tetra-20 gallons
sPenguin Tetra-30 gallons
sCongo Tetra-30 gallons
aFiremouth Cichlid-40 gallons
aTexas Cichlid-50 gallons
aRed Devil Cichlid-55 gallons
aSeverum Cichlid-40 gallons
Apistogramma-30 gallons
Cockatoo Cichlid-30 gallons
aSalvini Cichlid-50 gallons
aMaganuese/Jaguar Cichlid-75 gallons
aFlowerhorn Cichlid-70 gallons
aPeacock Bass Cichlid-100 gallons
Port Acara Cichlid-30 gallons
aGeophagus Cichlid-50 gallons
aGreen Terror-55 gallons
Keyhole Cichlid-40 gallons
Red Breast Smiling Cichlid-30 gallons
Mousquito Fish-20 gallns
Bitterling-30 gallons
aIndian Dwarf Puffer-5 gallons for the first,5 more for every after
Badis-20 gallons
aAfrican Butterfly Fish-30 gallons
Elephant Nose-50 gallons
aLeapord Ctenopoma-50 gallons
Celebes Half Beak-30 gallons
American Flagfish-10 gallons
aCrocodile Fish-40 gallons
bFahaka Puffer-125 gallons
Fire Eel-75 gallons
Freshwater Pipefish-30 gallons
Glass Knife Fish-125 gallons
Gold Datnoid-150 gallons
aNeedle Nose Gar-100 gallons
Peacock Gudgeon-20 gallons
Peppermint Crocodile Fish-30 gallons
a,bPrehistoric Dragon Goby-100 gallons
aRed Tail Barracuda-75 gallons
Red Fin Prochilodus-100 gallons
Rope fish-100 gallons
Sturgeon-250 gallons
Tire Track Eel-150 gallons
Zig Zag Yellow Tail Eel-50 gallons
bBumblebee Goby-10 gallons
bFigure Eight Puffer-30 gallons
bMono Sebae-50 gallons
bMono Argentus-75 gallons
bRuby Scat-75 gallons
bArcher Fish-100 gallons
Feel free to add to the list
s=schoolers,need groups of 6 or more
a-aggressive
b=brackish,require marine salt to survive
Fancy Goldfish-20 gallons for one,10 for every after the first
Common Goldfish-55 gallons for one
sRosy Red Minnow-20 gallons
Koi-500 gallons for one,need ponds or huge tanks
aOscar-75 gallons for one
aJack Dempsey-55 gallons for one
Parrot Cichlid-40 gallons
Convict Cichlid-29 gallons
sColombian Tetra-20 gallons
Platy-20 gallons
Guppy-10 gallons
Molly-29 gallons
sUpside Down Catfish-20 gallons
sGlowlight Tetra-20 gallons
sLamp Eye Tetra-20 gallons
sRed Minor Tetra-20 gallons
sVon rio Flame tetra- 20 gallons
sBlack Phantom Tetra-30 gallons
sX ray Tetra- 20 gallons
sMarble Hatchetfish-20 gallons
sSilver Hatchetfish-20 gallons
sMarthae Silver Hatchet-10 gallons
sNeon Tetra-20 gallons
sCardinal Tetra-20 gallons
sGiant Danio-30 gallons
sHarlequin Rasbora-20 gallons
sScissortail Rasbora-20 gallons
sWhite Cloud-20 gallons
sGhost Catfish-30 gallons
sCory-20 gallons
sPygmy Cory-5 gallons
sOtoclinus-10 gallons
Common/Sailfin Pleco-125 gallons
Bristlenose Pleco-20 gallons
Rubber Lip Pleco-30 gallons
sSkirt Tetra-30 gallons
Honey Gourami-20 gallons
Dwarf Gourami-20 gallons
sBuenos Aires Tetra-20 gallons
sBoseami Rainbow-55 gallons
sBloodfin Tetra-20 gallons
sBleeding Heart Tetra-30 gallons
sKhuli Loach-20 gallons
Swordtail-40 gallons
sGlofish-20 gallons
sZebra Danio-20 gallons
sBala Shark-150 gallons
sClown Loach-150 gallons
Pictus Catfish-55 gallons
sRosy Barb-30 gallons
sCherry Barb-20 gallons
sSilver Dollar-125 gallons
sTinfoil Barb-100 gallons
sTiger Barb-30 gallons
Opaline Gourami-30 gallons
Blue Gourami-30 gallons
Betta- 5 gallons
aChinese Algae Eater-55 gallons
aAfrican Brown Knife-100 gallons
aBlack Ghost Knife-125 gallons
Angelfish-30 gallons
aDinosaur Bichir-55 gallons
aRed Tailed Shark-55 gallons
sCelesyial Pearl Danio-5 gallons
sChili Rasbora-5 gallons
Scarlet Badis-5 gallon
Ram-20 gallons
sOdessa Barb-30 gallons
sDension Barb-50 gallons
aOrnate Bichir-75 gallons
sTurqoise Danio-20 gallons
sGlowlight Danio-20 gallons
sDiscus-50 gallons
Redtail Catfish-300 gallons
Silver Arowana-300 gallons
Banded Leporinus-70 gallons
aAfrican Tiger Fish-500 gallons
Pacu-300 gallons
aPiranha-250 gallons
Sparkling Gourami-10 gallons
Pearl Gourami-30 gallons
Blue Paradise Fish-30 gallons
Black Molly-55 gallons
Kissing Gourami-100 gallons
Gold Gourami-30 gallons
Chocolate Gourami-30 gallons
Licorice Gourami-20 gallons
Giant Gourami-100 gallons
Clown Killifish-20 gallons
Gardneri Panchax Killifish-20 gallons
Golden Dream Panchax Killifish-20 gallons
Least Killifish-5 gallons
Striped Raphael Catfish-40 gallon breeder,55 gallons
Reticulated Hillstream Loach-30 gallons
Zebra Pleco-30 gallons
sPraecox Rainbow-20 gallons
sThreadfin Rainbow-10 gallons
Siamese Algae Eater-30 gallons
bColombian Shark-70 gallons
Rainbow Shark-50 gallons
Golden Algae Eater-50 gallons
Whiptail Catfish-50 gallons
sRumynose Tetra-20 gallons
sSilver Tip Tetra-20 gallons
sGreen Fire Tetra-20 gallons
sEmperor Tetra-20 gallons
sHead and Tail Light Tetra-20 gallons
sPenguin Tetra-30 gallons
sCongo Tetra-30 gallons
aFiremouth Cichlid-40 gallons
aTexas Cichlid-50 gallons
aRed Devil Cichlid-55 gallons
aSeverum Cichlid-40 gallons
Apistogramma-30 gallons
Cockatoo Cichlid-30 gallons
aSalvini Cichlid-50 gallons
aMaganuese/Jaguar Cichlid-75 gallons
aFlowerhorn Cichlid-70 gallons
aPeacock Bass Cichlid-100 gallons
Port Acara Cichlid-30 gallons
aGeophagus Cichlid-50 gallons
aGreen Terror-55 gallons
Keyhole Cichlid-40 gallons
Red Breast Smiling Cichlid-30 gallons
Mousquito Fish-20 gallns
Bitterling-30 gallons
aIndian Dwarf Puffer-5 gallons for the first,5 more for every after
Badis-20 gallons
aAfrican Butterfly Fish-30 gallons
Elephant Nose-50 gallons
aLeapord Ctenopoma-50 gallons
Celebes Half Beak-30 gallons
American Flagfish-10 gallons
aCrocodile Fish-40 gallons
bFahaka Puffer-125 gallons
Fire Eel-75 gallons
Freshwater Pipefish-30 gallons
Glass Knife Fish-125 gallons
Gold Datnoid-150 gallons
aNeedle Nose Gar-100 gallons
Peacock Gudgeon-20 gallons
Peppermint Crocodile Fish-30 gallons
a,bPrehistoric Dragon Goby-100 gallons
aRed Tail Barracuda-75 gallons
Red Fin Prochilodus-100 gallons
Rope fish-100 gallons
Sturgeon-250 gallons
Tire Track Eel-150 gallons
Zig Zag Yellow Tail Eel-50 gallons
bBumblebee Goby-10 gallons
bFigure Eight Puffer-30 gallons
bMono Sebae-50 gallons
bMono Argentus-75 gallons
bRuby Scat-75 gallons
bArcher Fish-100 gallons