All fish are more prolific during warm weather.
Practically all fish will eat young fry.
Algae—a fine green plant growth—is caused by an excess of light. Remove as much of the growth as possible and reduce amount of light.
Floating algae—green water—is caused by the same condition. Cut down light and condition usually clears itself. (See [page 4].) Coloring water in tank a faint pink with a solution of potassium permanganate will usually clear this condition. Green water is actual healthy water for fish.
Algae may be cleaned off glass by scraping with safety razor blade. ([Fig. 8].)
Cloudy water usually caused by improperly balanced tank. Remedy: more plants or less fish, better light, more scavengers, less food.
FIG·8
Cloud at bottom of tank is usually caused by decaying of excess food.
Plants thrive better in deep sand; roots spread and absorb decaying matter.