Guppy Troubleshooter

Having trouble figuring out what is happening to your guppies? Go through this checklist may help you discover the nature of the problem.

Many diseases can be also be avoided by limiting the amount of stress that a fish endures when they are newly acquired and during day-to-day care. Here is an article on stress, and it's role in fish diseases.

Frequent observation and immediate action to correct a problem will help eliminate the possibility of the spread of a disease and will greatly improve the odds of your fish recovering. In other words, if you see something wrong with your fish - act on it!!


What is your pH? Any sudden changes in temperature or pH? See Water Quality .

Do you use salt as a general additive?

What temperature is your guppy tank?

Any sudden recent water temperature fluctuations of more than 4 degrees?

Has anything been done to the tank that is out of the ordinary? Such as changes in water changing practices or addition of new fish or plants, use of live food, new tank decorations?

Is there a possibility of any of the following being in contact with the fish tank: aerosol sprays, paint fumes, tobacco, other fumes or chemicals, metal of any kind? See Water Quality .

Any new piping or plumbing or mains work by the local water supply company (such as the addition of chloramines)?

What is the size of the tank(s) involved and the stocking level?

What is your method(s) of filtration? How often do you make partial water changes? How often do you rinse the filter or change it?

What types of food do you feed and how often?

Purple Delta2. MORE DETAIL

When did the problem start?

How many fish are affected?

What action did you take?

What medications have you tried?


N/R = No Remedy

Q= Quarantine Note: most sick fish should be quarantined. This is added where it is especially important.


Split, often in middle as if cut

"Split tail" - should heal naturally, various causes: check for sharp ornaments, fighting. Could be caused by large water changes, weak genetics.Watch for fungus

Ragged, deteriorating with whiteish or red edge

Bacterial tail rot. Q Ailments

Clamped or closed (pin-tail)

Check water quality (i.e.ammonia). If no problem, likely body Flukes Parasites


Bulge, bump

Tumour, not threatening, N/R

Smooth, yellow/white cyst

Nodular disease caused by spores.Can be introduced by live tubifex worms.N/R.Q/DESTROY

Cauliflower-like growth, starts as cyst

Lymphocystis, caused by virus. Destructive but uncommon in freshwater tanks. Can be transmitted & will grow. Q/DESTROY (may try Quick Cure)

White cottony patches or white discolouration on lips or body

See fungus and columnaris Ailments

Slimey, cloudy skin

Sliminess of the skin (excess body mucus) Parasites

Lesions, ulcers or sores, reddening at base of fins/vent

Haemorrhagic Septicaemia, Q - see Ailments

White salt-like specks over entire body

White spot (Ich)  Parasites

Yellow/grey/gold dust, peeling skin, loss of appetite

Velvet Disease Parasites

Tiny sand-like spots, peeling skin, difficulty swimming, protruding scales

Guppy Disease Parasites

Reddish worms protruding from anus

Camallanus Q Parasites

Thin, pale, bent back, pop-eye, ulcers, listlessness, sores, fin rot

TB - Q/DESTROY - See TB information under Ailments

Swollen, protruding scales (usually), sometimes pop-eye

Dropsy Q Ailments

Bent, malformed spine

Could be genetics,TB or malnutrition N/R


Gasping for air

Poor water quality Water Quality

Reddened, inflamed, rapid movement

Gill parasite Parasites or water quality Water Quality


Protruding from head

See TB, Dropsy, Pop-eye Q N/R Ailments




"Flashing" - quickly scratching body on surfaces

Check for ammonia and other toxins ( Water Quality ) - External Parasites Parasites

Unnatural swimming, floating

Swimbladder complications N/R Ailments

Fish is vertical (head-standing)

Swimbladder inflamation Ailments

Loss of appetite, spits out food

Tainted/stale food? - Stressed? - Internal problems - See TB, camallanus, dropsy

Listless, inactive, surface resting, gasping, jumping, sporadic movements

Water quality problems - or other causes. Water Quality or Parasites

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