Care library / Health

Health guide, not a diagnosis · Serious if left

Fin rot

Also called tail rot

Signs

Ragged, shrinking or white-edged fins
Red or black fin edges
Lethargy

Cause

Bacteria that attack fins when water quality is poor or fins are damaged by nipping.

What to do

Test water and do water changes first. Mild cases heal with clean water; severe cases need an antibacterial treatment.

If a fish is badly ill, talk to an aquatic vet.

Prevention

Weekly water changes, no fin-nipping tankmates.

Medicines used for it

Always read the label first

Antibacterial treatmentsAntibacterial

Herbal remediesAntibacterial

Species often affected

278 species

Cardinal tetraParacheirodon axelrodi

Moderate3 cm23–29 °C

Black neon tetraHyphessobrycon herbertaxelrodi

Easy3.2 cm20–28 °C

Black skirt tetraGymnocorymbus ternetzi

Easy7.5 cm20–26 °C

Serpae tetraMegalamphodus eques

Easy4 cm22–27 °C

X-ray tetraPristella maxillaris

Easy4.5 cm24–28 °C

Lemon tetraHyphessobrycon pulchripinnis

Easy3.8 cm22–28 °C

Congo tetraPhenacogrammus interruptus

Moderate8 cm23–28 °C

Glowlight tetraHemigrammus erythrozonus

Easy4 cm24–28 °C

Rummy-nose tetraPetitella rhodostoma

Moderate5 cm24–27 °C

Ember tetraHyphessobrycon amandae

Easy2 cm24–28 °C

Bloodfin tetraAphyocharax anisitsi

Easy5.5 cm18–28 °C

Emperor tetraNematobrycon palmeri

Easy4.2 cm23–27 °C

Penguin tetraThayeria boehlkei

Easy6 cm22–28 °C

Head and tail light tetraHolopristis ocellifera

Easy4.5 cm24–28 °C

Bleeding heart tetraMegalamphodus erythrostigma

Moderate6.1 cm22–28 °C

Tiger barbPuntigrus tetrazona

Easy7 cm20–26 °C

Cherry barbRohanella titteya

Easy5 cm23–27 °C

Rosy barbPethia conchonius

Easy10 cm16–24 °C

Odessa barbPethia padamya

Easy4.6 cm16–25 °C

Gold barbBarbodes semifasciolatus

Easy7 cm18–24 °C

Denison barbDawkinsia denisonii

Moderate15 cm18–25 °C

Black ruby barbPethia nigrofasciata

Easy6 cm20–27 °C

Tinfoil barbBarbonymus schwanefeldii

Hard35 cm20–28 °C

Zebra danioDanio rerio

Easy5 cm18–25 °C

Celestial pearl danioDanio margaritatus

Moderate2.1 cm20–25 °C

Giant danioDevario aequipinnatus

Moderate10 cm16–26 °C

Harlequin rasboraTrigonostigma heteromorpha

Easy4.5 cm22–27 °C

Lambchop rasboraTrigonostigma espei

Easy3 cm23–28 °C

Chili rasboraBoraras brigittae

Moderate2 cm24–28 °C

Scissortail rasboraRasbora trilineata

Moderate13 cm22–25 °C

GuppyPoecilia reticulata

Easy6 cm22–28 °C

Endler's livebearerPoecilia wingei

Easy2 cm24–28 °C

PlatyXiphophorus maculatus

Easy6 cm20–26 °C

Variatus platyXiphophorus variatus

Easy7 cm20–26 °C

SwordtailXiphophorus hellerii

Moderate14 cm22–28 °C

MollyPoecilia sphenops

Easy8 cm24–28 °C

BettaBetta splendens

Easy6.5 cm24–28 °C

Dwarf gouramiTrichogaster lalius

Easy9.5 cm22–27 °C

Honey gouramiTrichogaster chuna

Easy5.5 cm22–27 °C

Pearl gouramiTrichopodus leerii

Easy12 cm24–28 °C

Three-spot gouramiTrichopodus trichopterus

Easy15 cm24–30 °C

Kissing gouramiHelostoma temminckii

Moderate30 cm22–30 °C

Sparkling gouramiTrichopsis pumila

Easy4 cm24–28 °C

Giant gouramiOsphronemus goramy

Moderate70 cm22–28 °C

Paradise fishMacropodus opercularis

Moderate6.7 cm10–22 °C

Bronze corydorasOsteogaster aenea

Easy7.5 cm22–26 °C

Panda corydorasHoplisoma panda

Easy5 cm22–25 °C

Sterbai corydorasHoplisoma sterbai

Easy6.5 cm24–28 °C

Julii corydorasHoplisoma trilineatum

Easy6 cm22–26 °C

Pygmy corydorasGastrodermus pygmaeus

Moderate2.5 cm22–26 °C

Bristlenose plecoAncistrus cf. cirrhosus

Easy13 cm21–26 °C

Common plecoPterygoplichthys pardalis

Moderate50 cm20–28 °C

Zebra plecoHypancistrus zebra

Moderate8 cm26–30 °C

Gold nugget plecoBaryancistrus xanthellus

Moderate22 cm27–32 °C

Royal plecoPanaque nigrolineatus

Hard43 cm22–26 °C

Clown plecoPanaqolus maccus

Easy9 cm23–28 °C

Glass catfishKryptopterus vitreolus

Moderate6.5 cm20–26 °C

Upside-down catfishSynodontis nigriventris

Moderate10 cm24–28 °C

Red tail catfishPhractocephalus hemioliopterus

Hard130 cm21–26 °C

Tiger shovelnose catfishPseudoplatystoma fasciatum

Hard100 cm22–26 °C