Fish Disease Advice Sheet

Fish Disease Advice Sheet

Most living organisms can suffer illness at one time or another. The most effective way to deal with this reality is to prevent, rather than wait for a possible problem. The consequences of having to treat a stocked aquarium with a medication can be stressful and damaging in itself. Many plants, fish and helpful bacteria can suffer as a result of using medication.

You need to get to know your fish well if you are going to be able to spot disease or illness before it becomes untreatable, so spend time observing your fish, how they move and interact with their environment.

The following list provides general points that support disease prevention:

1 Choose only healthy fish, avoid purchases from aquariums containing sick fish.
2 Purchase fish in limited groups, slowly build fish populations.
3 Consider a quarantine aquarium. This will allow observation and preventative treatments before exposing new fish to established aquarium inhabitants.
4 Follow proper acclimatisation of new specimens.
5 Always condition new water with Aqua Plus before adding to the aquarium. Chlorine, chloramine, and metals are damaging to aquarium inhabitants.
6 Perform basic water tests and maintenance on a regular basis.
7 After power failures, ensure that all equipment is working properly. Observe fish carefully, temperature variations will stress them.
8 Regular illumination periods are important for fish and plants. Switch lights on and
off at the same time every day or use an automatic timer.
9 If a medication has been used, after the treatment is complete, perform additional
water changes and use carbon filter media to remove residual traces. Test water and dose with Cycle and Aqua Plus. (NB. Carbon should always be removed from the filter during medication and replaced only when treatment is complete).
10 Supply regular feedings of various quality foods.

If you see any variation, the first thing to do is to check water quality as it may be a sign of pollution or poor water conditions. If this is not the problem you will need to seek advice from an authority on fish - your local supplier for instance.

Test Kits Tropical Food Internal Filters
External Filters Tropical Heaters Tropical Treatments
Tropical Air Pumps Tropical Lighting Tropical Accessories

Common Mistakes

If you are experiencing disease problems in your tank then there are a number of commonly made mistakes that could be to blame:

1. Cleaning the filter foams with tap water: tap water contains chlorine that will kill off the beneficial bacteria that live in the filter. This will result in a build up of ammonia and nitrite. Filter foams should be rinsed in a jug of water from your tank.

2. Over-feeding: Feeding your fish too much will result in excessive levels of solid waste being produced. This will lead to deteriorating water quality and the encouragement of disease causing organisms. Fish should be fed no more than two to three times a day, feeding no more than they consume within a few minutes

3. Dirty Gravel: If the gravel is allowed to get very dirty it will provide an environment in which certain disease causing organisms will thrive. It will also lead to increased levels of pollutants and a decrease in the oxygen levels. Gravel should be kept clean through the use of a TetratecHydroclean gravel siphon.

4. Over-stocking: If you have too many fish in the tank then the filter will have a harder time maintaining good water quality. There may also not be enough oxygen in a heavily stocked tank, in which case a Tetratec Whisper air pump should be added. Physical damage is also more common in over-stocked tanks, and the levels of stress tend to be higher as well. If your tank is too heavily stocked then you will either have to buy a bigger home for your fish, or upgrade the equipment.

5. Incompatibility: If you have fish that are incompatible, then health problems may arise. Often problems can be attributed to one particular fish that is bullying the others. Look out for signs of aggression and always make sure that fish are compatible before you buy them. If you already have an aggressive fish then you will have to find a new home for it.

6. Damaging décor: If your tank contains a lot of sharp objects then there is a danger that the fish will damage themselves on them. This often occurs when they are startled and they dart to safety, knocking into the tank decorations. Physical damage caused in this way can quickly lead to infection, and therefore the offending items should be removed from the tank.

7. Not conditioning tap water: When adding tap water to the tank, it should always be conditioned with Tetra AquaSafe in order to neutralise its harmful chlorine and heavy metal content. Failure to do this will result in damage to the fishes’ gills, ultimately leading to health problems.

These are just some of the more common mistakes to avoid, it may be that in some cases the cause of a problem requires further investigation. In such cases we would advise talking to your local aquatics outlet.


White Spot Disease
A common ailment that responds to treatment well, although it is best to treat the whole tank.

Look for torn, ragged or stuck- together fins. Try to treat at early stage - if the rot reaches the body, cure is unlikely.

Velvet Disease
Infected fish have a dusty look, the treatment is similar to White Spot.

Skin/Gill Flukes
Watch for fish scratching themselves on rocks or plants, this nasty parasite causes colour to fade and fish to become feeble - they may rest near the surface. It responds well to treatment.

Slimy Skin
A thin grey film that covers their body - usually in response to parasites.

White spots that join to form patches. Fish become emaciated and twisted - often caused by poor condition and food.

Usually only attacks fish weakened by other poor conditions, disease or parasites. Healthy fish will not be affected.

Mouth Fungus
Unlike body fungus, this requires specific treatment.

Eye Infections
Cloudy, protruding eyes could be the sign of fungus, bacteria, parasites or even fish tuberculosis.

Highly contagious and difficult to cure, the fish's body can become so bloated that the scales protrude. Sick fish must be removed at once.

Fungal infections often arise at the site of any physical damage sustained by the fish. They can also occur as “secondary infections” at sites where there is an existing infection (for instance around ulcers). Fungus is present at low levels in the tank all of the time, and it is only when the fish is stressed or damaged that it tends to cause a problem. TetraMedica FungiStop is a remedy specifically designed to cure fungal diseases.

Parasitic infections are those caused by parasites. Parasites come in a variety of shapes and forms, and it is usually necessary to examine them under a microscope in order to identify them. There are some common parasites that are easier to identify, for example white spot (Ichthyophthirius multifiliis) appears as small white dots over the skin and fins. Fish tanks that are very crowded, with poor water quality, are most at risk from parasite problems. TetraMedica ContraSpot is designed to cure the majority of fish parasite problems.