The Aquarium Troubleshooting Guide

Maintaining a healthy environment for your fish is the best defence against disease in the aquarium. Poor environmental conditions must be identified and corrected before beginning disease treatment. The most common environmental factors causing disease in aquarium fish are listed below. Most fish health problems will be attributable to one or more of these.

EXCESS AMMONIA & NITRITE

Toxic ammonia is continuously excreted by fish and is also produced through the breakdown of uneaten food, dead plants or fish. In an established and properly filtered aquarium, ammonia is broken down via nitrite into a harmless form by nitrifying bacteria. Filter media, gravel, rocks etc all act as a substrate for this process. When these beneficial bacteria are destroyed, or overwhelmed by excessive ammonia production, the increase in ammonia and nitrite causes stress and disease to aquarium inhabitants. Ammonia poisoning causes fin-rot, dropsy, external bleeding and gill disease. Catch the problem early - Use ammonia, nitrite and pH test kits. To dilute ammonia, make a 50% water change, test, and then repeat if necessary. The addition of Ammo-Carb resin will assist in the removal of ammonia, as will Ammo-Lock liquid. To increase the levels of ammonia reducing bacteria, use Stress Zyme or Cycle.

'SPRING-CLEANING' THE AQUARIUM (complete water changes)

Although an aquarium will look very clean after a complete water change, it has in effect been sterilised. Nitrifying bacteria are destroyed, allowing a build up of toxic ammonia. To achieve a balanced environment for fish, make a partial water change of about twenty percent each fortnight, using an Aquarium Gravel Cleaner to remove debris.

Regular partial water changes are the key to a successful aquarium.

OVERFEEDING

The decomposition of uneaten food contributes to ammonia production, and in doing so depletes the aquarium of oxygen as colonies of nitrifying bacteria multiply to keep pace. Feed coldwater fish daily and tropicals twice daily, no more than will be consumed within one minute.

OVERCROWDING

Overcrowding an aquarium results in oxygen depletion and the production of excessive organic waste, followed by ammonia poisoning. The following maximum stocking levels must be achieved gradually.

. Tropical 1 cm of fish per 25 cm2 of surface area.

. Coldwater 1 cm of fish per 75 cm2 of surface area.

. Marine 1 cm of fish per 120 cm2 of surface area.

INADEQUATE FILTRATION

Many diseases of fish are caused by a lack of or inadequate filtration. To perform efficiently a filter needs to turn over approximately four times the aquarium volume per hour. Undergravel filter plates should cover at least 75% of the aquarium base and are not suitable for very tall aquariums with a low surface to volume ratio. All filters must run continuously. Filter inserts are best cleaned in dechlorinated water to avoid destroying beneficial bacteria. Activated carbon and resin media should be replaced every six to eight weeks. Power filters are very efficient and are one of the aquarists most important tools for maintaining healthy fish.

OXYGEN DEPLETION

Oxygen depletion is typically indicated by fish gasping at the surface of the aquarium. This occurs as a result of overfeeding, overcrowding or inadequate filtration as discussed above. Rising temperature is also a factor as the oxygen content of water becomes progressively less with increasing temperatures.

UNSUITABLE PH

pH is a measure of the acidity or alkalinity of the water. Most tropicals can be kept successfully at a nuetral pH of 7.0. Goldfish prefer a slightly alkaline pH of 7.5. Sudden changes in pH or significant deviations from ideal conditions will cause pH burn, which can be fatal to fish. At a higher pH, ammonia increases in toxicity. Avoid using anything from the beach in a freshwater aquarium. The limestone from coral, seashells and some rocks will dissolve, causing the water to become extremely alkaline. Ornaments made of concrete or plaster can have a similar effect.

TEMPERATURE

Check that the heater is operating properly and holding the correct temperature. 79 degrees farenheight is suitable for most tropicals. Temperature fluctuations in coldwater or tropical fish can cause disease.

A FURTHER CHECKLIST

. Is the aquarium near a constant source of vibration? Eg slamming door, TV, stereo, speaker, heavy foot traffic, knocking on glass etc.

. Has a poisonous chemical entered the water? Eg aerosol sprays, tobacco or paint fumes, cleaning products etc.

. Has excessive handling of the fish taken place?

. Are fish compatible? Is there a pecking order resulting in some fish being killed by tankmates?

Disease causing organisms are always present at a low density in the aquarium. Poor environmental conditions result in stress to fish, allowing these organisms to overwhelm the fishes natural immunity. Proper care and a small amount of regular maintenance will greatly lower the incidence of disease.