At the very beginning of this discussion I want to say that none of the diseases or parasites which sometimes plague goldfish affect human beings. Hygienic precautions should be taken by anyone handling sick goldfish, but only against transferring trouble from one fish to another. There are, indeed, many types of misfortune which can befall goldfish, but take heart, for all of these things are not going to happen to your goldfish. In fact, if you keep a pool or an aquarium for the next fifty years, you probably won't run into more than a very small percentage of them. As in any health program, prevention is far more effective than remedial treatment. Here are a few measures which will keep the health of your pool or aquarium at the highest possible level.

1. Observe at all times the advice given as to capacity of container, temperature of water, and feeding of fish.

2. Before introducing new aquatic plants, sterilize them as outlined in Chapter 18.

3. Before adding new goldfish to pool or aquarium, regardless of where you bought them, sterilize them, too, for an hour or two in a potassium permanganate solution, 1/8 grain per gallon of water. Like other dealers, I sell a prepared fish dip, which is also an effective sterilizing agent.

4. Watch for drooping dorsal fins (on fish which normally hold them stiff), for sluggishness, congested fins, and excrement containing slime or bubbles. Isolate ailing fish immediately and treat according to symptoms.

5. Also sterilize dip-nets and containers used for treating fish with the potassium permanganate solution mentioned above.

Ailing fish removed for treatment should be kept in a broad, shallow receptacle in only 2 to 3 inches of water. A dishpan makes an excellent sick bay, and so does a used washtub or partially filled goldfish bowl. Have the water in the treatment receptacle of the same temperature, as closely as you can judge, as that in which the fish have been living. Keep ailing fish out of strong light, and suspend feeding unless otherwise specified, while they are being treated.

Any tired, sluggish fish seem to revive immediately upon transfer to different water. This water, if green, is all the more beneficial. A good provision to make for treatment is a spare aquarium planted with a few oxygenating plants and kept ready for use. Otherwise, obtain green water from your own or from a neighbor's pool, or from a stream where fish are known to live.

For the lesser ills, as a run-down condition, transfer the fish for a few days to shallow temporary quarters, such as an old washtub, with 2 to 3 inches of mud in the bottom. This is wonderfully invigorating. Put a few sprigs of oxygenating plants and a snail or two in the tub to make it more livable.

For some reason which nobody can yet explain, run-down goldfish perk up amazingly when placed in a container fed by a drip or trickle of water. Ailing fish, apparently on the verge of breakdown with something serious, can often be brought back to perfect health in two or three days of this treatment. Kept there long enough, fish show appreciable increase in growth.

The drip-fed container, incidentally, is a fine device for tapering down gradually any strong salt solution (given below) in which a fish has been placed.