The Aquarium and Pond Active Online Publication

Mastering Freshwater Aquarium Ecosystems

Table of Contents

  1. COVER
  2. INTRODUCTION
  3. FRESHWATER
  4. NITROGEN CYCLE
  5. WATER TESTING
  6. ADJUSTING WATER CHEMISTRY
  7. TOP OFF WATER
  8. WATER CHANGES
  9. CHOOSING THE AQUARIUM
  10. LIGHTING
  11. FILTRATION
  12. AQUARIUM EQUIPMENT
  13. SUBSTRATE
  14. ROCKS
  15. WOOD
  16. PLANTS
  17. BIOTOPES
  18. FISH SELECTION
  19. FISH FOOD AND FEEDING
  20. CHOOSING FISH
  21. FISH HEALTH
  22. AQUARIUM CLUBS
  23. REFERENCES
  24. QUESTIONNAIRE
58%

Rocks

Many fish come from areas where there are a lot of rocks. Many of these fish use the rocks for shelter, reproduction, and harvesting food. Most of the African rift lake cichlids seen in the hobby today live in areas of the lakes that have large rocky reefs. These fish use the rocks for shelter and spawning surface to deposit their eggs. Many of the fish eat algae that grow on the rocks. Many cichlids from Central America are also adapted to an environment that has a lot of rocks. Riverbed rocks are an excellent decor for these types of fish.

Rocks
Rocks stacked along the back of this 240 gallon (912 l) aquarium provide a refuge for juvenile Tanganyikan cichlids.

Many cichlids, like oscars (Astronotus ocellatus), Jack Dempseys (Rocio octofasciata), rainbow cichlid (Herotilapia multispinosa), dwarf flag cichlids (Laetacara curviceps), and rams (Mikrogeophagus ramierzi) will use a flat rock as a spawning surface.

Rocks can be purchased from rock/landscape suppliers or aquarium and pet shops. They can also be collected at many different locations at no cost. Most rocks are neutral, but some made of calcium carbonate will affect pH and hardness of the aquarium. Typically you will only need to scrub the rocks with a brush and tap water before placing them in the aquarium.

If you plan on stacking rocks in the aquarium, you should place them in contact with the bottom of the aquarium, so that if a fish digs, the rocks will not shift and tumble, possibly breaking the glass.

Rocks will eventually become colonized by aerobic bacteria. Rocks in an established aquarium can be used to help seed new aquarium setups with beneficial bacteria. The technique of moving rock to a new aquarium will often prevent the new aquarium from having an ammonia and nitrite spike.