Can I Use Petrified Wood for a Cichlid Aquarium?

Aquarists typically place pieces of wood into their aquariums to create a natural look and to provide fish with resting and hiding places. Cichlids are a very diverse group of tropical fresh water fishes. New world cichlids live in the soft, acidic rivers in America, while old world cichlids live in the hard, alkaline waters of Africa's great lakes. Petrified wood is not always easy to source, but most pieces are inert in water and can therefore be included in aquariums housing cichlids.

  1. Origins of Petrified Wood

    • Petrified wood originates from giant trees which grew 200 million years ago, during the Triassic Period. After dying, these trees became covered by mud, silt and sand. Water containing minerals eventually seeped into the hollow wood cells as the tree decomposed. Although this water evaporated, the mineral substances remained and through this process, preserved the form and texture of the original tree. Although the tree appears the same, an entirely different substance has replaced what was originally wood.

    Suitability for Aquariums

    • Petrified wood is no longer wood, but stone. In many cases, the replacement minerals are silica or quartz, but a number of other minerals, including opal, may have been involved. The chemistry of the groundwater gives petrified wood its distinctive colors. Although quartz is colorless, the piece of petrified wood may be stained by other minerals, such as iron. Petrified wood made up of quartz or silica is inert in the aquarium, but you should avoid pieces which were replaced by iron.

    Types of Petrified Wood

    • The majority of petrified wood has silicon as the replacement mineral. Petrified wood which has been replaced by silicon has a very realistic appearance, as opposed to that which has been replaced by calcite, which has a white appearance. Silicon replacement wood is composed mainly of opals, which are inert in any water chemistry and therefore suitable for any cichlid aquarium. Pieces of petrified wood found in Arizona are quartz-based and are termed "rainbow rocks."

    Choosing Petrified Wood

    • The pieces of petrified wood which are sold for aquarium use have inevitably been replaced by quartz or silica and are completely safe for use in your tank. Some pieces of petrified wood have been replaced by with carnotite, which is distinguished by its bright yellow appearance, and chalcopyrite, which has a metallic look. Don't use such pieces for cichlid aquariums. Unlike drift or bogwood, petrified wood is typically found in chunky pieces, but these can look very stunning if displayed prominently.