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Introducing new tropical fish to the aquarium

Introducing new topical fish into your aquarium is one of the riskiest procedures you will undertake as a fish keeper. The risks are many including upsetting the delicate eco-system in your aquarium, conflict between existing fish and the new fish and the introduction or disease. Great care must be taken when introuduing new fish and this basic guide will help you avoid the pit falls.

As a fish keeper it is extremely tempting to quickly replace any dead fish, you must only do so when you are sure that the dead fish has not died through disease which may still be in the aquarium or because your biological load on the filer was not to great.

Introducing Disease

You must take great care when selecting new fish, only purchase fish when you are 100% sure that they are healthy, key thing to look for are;

1. hanging at the top or sitting on the bottom of the tank
2. dull colour
3. rapid gill movements
4. damaged fins
5. red patches
6. dead or dying fish in the same aquarium

Ideally you should keep your new  fish in an isolation tank for at least 2 weeks preferably 4 weeks , provide some plants or rocks in this tank so they have somewhere to hide, remember un-stressed fish = healthy fish. Consider treating the new fish with an anti-parasite treatment but give them  few day to settle in the isolation tank before administering.

Maintaining a healthy aquarium

when you introduce your new fish into your aquarium you will undoubtedly upset the balance, typically you will see a small increase in ammonia and/or nitrite. Once you have introduced new fish into your aquarium you must test regularly and carry out water changes where necessary.

Avoiding conflict in the aquarium

Depending on the species of fish you keep you will see varying aggression to the newcomer : here are a few tips that can keep aggression to a minimum

1. Change the decor around in your new tank, the existing fish will be so busy with their new surroundings they will barely notice the newcomer
2. Introduce females  first, little or no aggression is shown to females
3. Move the isolation tank next to the existing aquarium so the fish can see each other
4. An extra feed, feed the fish just after you have introduced new fish in order to provide a distraction, avoid introducing newcomer at meal times when tensions are high.