Freshwater

Most tropical freshwater fish are inexpensive and pretty easy to keep, which
is why this is the best system for a beginning hobbyist. You can also purchase
an aquarium system at many superstores and pet stores in kit form. A
kit generally includes a tank, hood, filter, net, food, instruction book, and the
heater necessary for a tropical tank. A kit often doesn’t include gravel, plants,
or decorations that must be purchased separately. Always read the box label
so that you will know what extras you will need to buy to get the tank up and
running properly. Pet stores and large retail stores are great places to find
these starter kits, which are a good buy for the money.
Popular species of tropical freshwater fish include these:
Platys
Guppies
Mollies
Neons
Swordtails
Angelfish
Bettas
Tetras
Barbs
And that’s just to name a few.
Freshwater coldwater aquariums
A coldwater aquarium usually houses species such as these:
Goldfish
Sunfish
Shiners
Bitterlings
Chapter 2: The Practice of Aquarium Keeping
In their native habitat, these fish normally live in lower temperatures than
their tropical counterparts. Large koi are often kept in coldwater ponds. The
equipment you need for a coldwater aquarium is similar to that for a tropical
aquarium, except that coldwater tanks don’t require a heating system. Larger
tanks are better for this type of system because coldwater species are generally
bigger than most tropicals and consume more oxygen.
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