The Skeptical Aquarist

In the freshwater zooplankton, the ciliates are perhaps the major group among the single-celled organisms, the protists. Though the notorious Ichthyophthirius multifiliis is a ciliate, most are free-living in the plankton, or form part of the biofilm.

There's no real savings in a cheap heater that's not completely submersible. There are many better ways to save money when you're setting up an aquarium than by buying a "bargain" heater.

Capillaria are parasitic nematodes, smaller than Camallanus and proportionately very thin ("capillaria" mean "hair-like"). There are numerous species, most of which were originally from South America, where they co-evolved with certain specific hosts.

Crustaceans, a huge division of the arthropods,fill most of the roles in water that insects fill on dry land. Crustaceans in the freshwater aquarium include colorful shrimp and copepods (Cyclops), a food for fry.

This variable fern is the major floating plant for most indoor aquaria. In the aquarium it's so fast-growing and undemanding that it gains a place on even a rank beginner's list.

This is an African fern that runs along a rhizome the way Java Fern does, and similarly it doesn't want its rhizome buried.