How to introduce new marine fish in the aquarium
To avoid long-term problems, research any fish or invertebrates you plan to purchase to make sure you can provide the right conditions for long-term maintenance.
Remember, it is much easier to put a fish in a reef tank than it is to take it out; Consider purchasing a specially designed fish trap to remove fish for treatment or relocation in case of problems.
Once you’ve made your selection and made sure your new purchase is properly packaged, the first step is to take your purchase home. To minimize temperature changes, a Styrofoam fish transport bag is ideal and can be purchased at your local store.
Be sure to get your new marine fish home quickly, as temperature fluctuations in a hot or cold car can be stressful.
the quarantine aquarium
Once home, unpack the new fish in low light and quiet conditions. Ideally, new fish should be placed in a quarantine tank to ensure that any problems can be treated in the absence of invertebrates, which would be harmed by medications.
Such a tank can be a very basic setup with an internal filter (matured in the main tank). Lighting for the aquarium is optional, but a tight-fitting lid will prevent fish from jumping out.
The temperature should be identical to the main aquarium, but the Specific Gravity can be lower, ideally around 1.020 to help control parasites.
Treatment with a copper-based medication will help minimize the risk of parasite outbreaks in the main aquarium if all new additions go through a two-week quarantine period.
Follow the technique below to move fish from the quarantine setup to the main tank.
Moving the new marine fish to the main aquarium
Using an ultraviolet sterilizer can help control parasites in the main tank. Invertebrates do not tend to suffer from these problems, but can be affected by predatory nudibranchs and molluscs. Hitchhikers like crabs and flatworms should also be removed before adding new inverts to the main aquarium.
To minimize the shock of transportation, empty the bag into a bucket or container that allows enough water to cover the fish or invertebrates.
Cover the bucket to prevent fish from jumping out, and pay close attention to avoid spills. With a 4mm long air line, it draws water from the marine aquarium to the bucket where the fish are.
Use a clamp or valve to limit flow when sensitive invertebrates are present. Crustaceans, such as cleaner shrimp, are often victims of osmotic shock caused by too rapid a change in salinity.
This is the most effective alternative method of acclimatization, as all water parameters can be equalized, minimizing stress.
Once the bucket or container is full and the Specific Gravity matches the destination tank, transfer the fish or invertebrates, ideally using a smaller container. It may be necessary to remove some of the water from the small buckets and add more aquarium water to ensure full acclimation.
Some invertebrates should never be removed from the water and exposed to air, as this will cause internal damage; primarily these include echinoderms (such as starfish and sea urchins) and sponges. It is good practice to keep all corals and anemones submerged, as they are unable to support their own weight out of the water and are easily damaged.
Discard the water in the bucket and fill the tank with new water. When adding new invertebrates to the main tank, care must be taken to ensure correct placement in terms of lighting and current. Corals may object to a major change in lighting conditions and some adjustments may be necessary.
Turbo snails should be placed on a hard surface, as they may be unable to move on loose substrate and are unable to feed or seek shelter.
Beware of territorial aggression
The addition of new fish is complicated by territorial aggression, which is often directed towards newcomers. Add new fish with the lights off, and for very aggressive species, rearranging the rocks can help.
A mirror attached to the outside glass of the aquarium can serve to distract territorial fish by presenting them with a rival of their own kind. Newcomers are more likely to jump out of the aquarium than established specimens; make sure the aquarium is well covered.
Some species are particularly shy and can take up to a couple of weeks to settle down before confidently appearing in open water to feed; Adding food to the aquarium while the room is dark is a useful way to ensure nervous fish get a good meal.
As with all aquariums, adding new stock increases organic contaminant levels – make sure your aquarium is stocked at a consistent rate and monitor water quality. Remember that factors such as high levels of nitrates or salinity will be stressful for new additions without having the same effect on animals more accustomed to poor conditions.