It is much easier to keep fish healthy than to cure them.

Disturb your fish as little as possible.

Fish in good health are active and keep dorsal fin erect. (Folded fins for a short period do not mean a sick fish.)

Most fish ills develop from chills. Keep fish above lowest safe temperature. Young fry especially should be kept warm.

Avoid extremes of temperature. Avoid sudden changes of temperature. Provide some type of aquarium heater for cold months.

Do not crowd fish—be sure plants are thriving and there is ample oxygen in water.

Fish constantly at top indicate foul water and lack of oxygen. Remove part of water and replace with fresh of same temperature.

Dying plants cause much trouble—be sure plants are healthy and growing.

It is much easier to keep fish healthy in a large tank (above 5 gallons). A large tank maintains a more uniform temperature, allows more air surface, plants thrive better, and water is not fouled so easily by excess food.

An aquarium can be maintained in healthy condition, both plants and fish thriving, under artificial lighting furnished by an ordinary light bulb.

Vary the diet for the fish. Feed only as much as they will eat in ten minutes. Feed sparingly and several times a day if necessary. Use glass feeding ring. (Fig. 4). All uneaten food drops to one spot where it can be easily removed with a dip tube.

Health and growth of fry depend upon oxygen supply. Use tank with large air surface. BE SURE AND DO NOT CROWD YOUNG FRY. Crowding stunts growth and frequently causes disease, and loss of whole brood. Fry demand approximately same amount of water as adults—see page 31.