Dressing up the aquarium with a bit of greenery is the next step, and oxygenating plants for this purpose are discussed in Chapter 12. Some fanciers advise a plant for every square inch of aquarium floor. The plants need not be dispersed over the entire floor, of course, but can be arranged artistically in clumps and borders, much as marginal plants are arranged around an outdoor pool.

Others maintain that one aquatic plant for every 4 square inches of aquarium floor is enough. In my own aquariums, I plant at a rate about halfway between these two schools of thought, and mine are so balanced that they do not need frequent changes of water.

Before planting any aquatics in aquarium or pool, trim off all dead leaves and branches and examine each plant carefully for insects or eggs. You can play doubly safe, as I do, by immersing all new plantings of aquatics in disinfectant before introducing them to your pool or aquarium. I use household ammonia and water in a 1 to 50 mixture (4 teaspoons to 1 quart or 1 cup to 3 gallons) and let the plants soak in this for two hours.

Buy any of the hardy breeds of goldfish at any time of year. Select them for beauty and generally healthy appearance. Age is not much of a factor with these breeds, for in an aquarium the lifespan ranges from 10 to 20 years. In outdoor pools, they often live beyond the age of 30 years.

The size of the hardy goldfish you select will also be a matter of personal choice. Remember that goldfish have the characteristic of adapting growth to surroundings. They grow slowly, if at all, in a small aquarium. The larger the aquarium or pool, the larger they will grow.

The fancy breeds require a little shopping. Age is a factor with these fish, for their lifespan in an aquarium (few are considered hardy enough for outdoor pools) ranges from only 6 to 12 years.

Early or mid-autumn is a good time to buy these fancy breeds. A fancy fish 1 1/2 to 2 inches long (excluding tail) at that time will probably have been hatched only the preceding spring. At this age, they are ideal stock with which to start, big enough to stand the shock of being moved into a now aquarium, still so young that they do not yet show their distinctive tail and fin developments. If you are interested in fancy fish at all, you will undoubtedly want to see their growth from the very beginning.

Buy a fully developed fancy fish, by all means, if one catches your eye. But remember that once a fancy fish has achieved its most beautiful fin and tail forms, the remaining years will be declining years.

Disinfect new goldfish, too, as you did the aquatics, before putting them into their new home. A two-hour in a solution of potassium permanganate, 1/8-grain tablet (from the drugstore) to 1 gallon of water, will kill almost any bacteria they may have brought along and also help them recover from the shock of moving.