SEAWEEDS & ALGAES
Seaweeds are an important part of natural temperate marine habitats and provide a home for a diverse range of invertebrates as well as add movement to your display. Subtidal red algae are the best for a closed system, with many attractive species available that will survive for varying periods of time in an aquarium.
The slow-growing, erect, encrusting coralline red algae are particularly attractive and suitable for aquarium life. Encrusting corallines form the beautiful pink patches coating rocks and will survive quite well under aquarium conditions. Other species of red algae may be tried and often do quite well, but should be removed when undergoing rapid loss of color or deterioration. Brown algae are used to a more rigorous environment that can be provided in the average aquarium and may cause problems if they begin decaying.
Temperate seaweeds that do well in the aquarium are generally subtidal species adapted to relatively low light levels. Most of these belong to the red algae group and make very attractive display additions.
A simple light system consisting of two fluorescent tubes (one actinic blue and one cool white are a good combination) on a 12-hour cycle should be adequate for a standard tank. Metal halide lamps can damage seaweeds collected from deeper levels than a rock pool.
All seaweeds should be collected with the holdfast intact. This attachment structure can be wedged into crevices or even glued with cyanoacrylic adhesives (super glue gel) onto the smooth surfaces of rocks (both surfaces must be dried with a paper towel before attempting to apply the glue).
In an aquarium with insufficient water motion, seaweeds may become fouled by algae and detritus so ensuring a good mixed flow in the water column is essential to keep them in their best condition. After all they are adapted for environments with a great deal of turbulence.
Coralline algae are hard and come in encrusting and upright branching varieties, extra calcium can be added to the aquarium to enhance growth, when collecting rocks try to avoid exposing them to air for too long a period as they can die off.
Green Grapeweed (Caulerpa geminata) is sometimes found in healthy rock pools or growing sub tidally. Its roots form a growing network so can be lifted off the rock it is on in a mat, this can be bound with cotton on rock work.
Strap Weed, Carpophyllum maschalocarpum Needs good varied flow , but slow grower.
Sea Rimu (Caulerpa brownii)This derives its name from the resemblance to the New Zealand rimu tree. Found sub tidally in medium shelter, East Coast North Island. This plant grows from runners, use Super Glue Gel or cotton to re attach.