Buying Your Fish

While your tank matures put the final touches to your shopping list of fishes, perhaps visiting local shops to check what is available and resisting any temptation to buy! You can, if you wish, reserve fishes, but expect to have to leave a deposit or even pay in full. It is, however, worth reserving only unusual species not generally available; remember too that come "the day" you may be left with the poorer- quality specimens no one else wanted.

You should already have calculated the number of fishes your aquarium can accommodate; you must now decide whether to introduce them all at once, or in stages (remember the filter will have to adjust to the increased loading). If you intend buying juveniles you will be imposing only a fraction of the planned eventual load, and can add them all at once. It may, however, be sensible to introduce adults in two or three batches with a few days between. It is usual to introduce marines a single fish at a time.

Before we discuss buying and introducing fishes, a few words on stress. Being caught, bagged, transported, and released into a strange environment is a highly stressful experience for a fish.

Stress can kill, so minimize the upset. Avoid buying fishes which have just arrived at the retailer's as they need time to recover from that last upheaval. Pick a quiet time for your shopping, when the dealer can give you his or her undivided attention. When buying fishes you are perfectly entitled to choose specific individuals, although in practice if there is little difference between most of a particular batch it is more appropriate to reject instead of select, simply refusing any which are deformed or undersized. Ask the dealer to hold each fish in the net against the tank front while you give it a final once-over. Never buy from a tank containing diseased or dead fishes ? the rest may be dead in a few days. Be particularly selective if buying breed ing stock: you want only the best, as poor quality parents usually produce poor quality fry which you won't be able to sell.

The dealer will pack your fishes in polythene bags, usually putting these in brown paper bags or a carrier so the fishes won't be frightened by what is going on around them. Fishes more than 7.5 cm (3 inches) long, and adults of territorial species (for example cichlids), should always be bagged singly to avoid murders in transit. If the dealer won't comply, shop elsewhere! Ideally take along suitably sized lidded buckets for very large specimens.

If you will be travelling some distance ask the dealer to "double bag" (in case of leaks) and to fill the air space in the bags with oxygen. For long journeys, or in very hot or cold weather, take along an insulated container a "cool box", a cardboard box lined with styrofoam, or a proper fish box borrowed from a friend. If you are buying a lot of fishes most dealers will supply a box if asked. Head for home straight away, and resist the temptation to keep checking the fishes in transit every time you let light in you will be causing stress.

On arriving home, remembering the need to avoid undue stress, keep handling to a minimum: take out each bag in turn, undo it, and float it in the tank to let the temperatures equalize. Secure the top by trapping it with the hood or clipping it to the tank edge with a clothes peg, otherwise it may sink and release the fishes prematurely. Repeat this process for the other bags. Equalization normally takes only minutes; check with a thermometer, and once the temperatures are within a degree or so of each other the fishes can be released. The longer a fish is floated, exposed and with nowhere to hide, the greater the stress, especially when the tank is already occupied by inquisitive fishes. Submerge the top of the bag, ensure it is wide open, then gently tip the fishes out. Always check they are all free!

Although you will be eager to watch your new pets, they will be frightened and confused, so turn the tank light off; the room light (or daylight) will suffice for them to settle in. Next morning turn theroom light on about 30 minutes before the tank light, and make this part of your normal routine. Never the other way round; sudden changes from "night" to "day" (and vice versa) are extremely stressful. Resist the temptation to feed your fishes for the first 24 hours; let them recover from their upheaval, then feed lightly, gradually increasing daily rations to maximum, so that the filter can take up the additional loading.

Subsequent Additions
If, after a few months, you want to add another fish or two (only if this doesn't mean overcrowding), you won't want to risk introducing disease, so it is worth investing in a quarantine tank. This must be large enough for its temporary inmate(s) and set up and matured as for a permanent aquarium, except that decor can be rudimentary, just enough to pro vide shelter. The water chemistry should be what the newcomer has been used to; adjust it (if necessary) to match your aquarium during the quarantine period (normally two to three weeks). This period will also allow the new fish(es) to recover from transit and adapt to your routine before meeting future tankmates.

Introducing New Fishes to the Aquarium
1
Undo the bag and float it in the aquarium to let the temperatures equalize. Secure the bag (for example with a clothes peg) so that it cannot sink and release the fishes prematurely.
2
When the temperatures are approximately equal (within a degree), submerge the neck of the bag, holding it wide open with one hand, and gently tip the fishes out.