Here is an article on caulerpa:
The case for Caulerpa
Caulerpa, the leafy green marine macro algae, has had a chequered past in the hobby. Once regarded
as impossible to grow in the confines of the aquarium it then became one of those infuriating aquarium subjects that would appear unwanted from nowhere and often have to be removed by
the bucketload Conversely, if you were keen to culture this rather attractive group of algae, your ef-forts would usually be met with failure.
Over the years, the number of
species available to Lobbyists have slowly risen from a single species, Caulerpa prolifera, to somewhere
in the region of 25 true species.
The choice of species can most often be a case of luck on the part
of the hobbyist as live rock is the most common means of introducing Caulerpa into a reef tank. live rock often contains dormant growths of plant organisms and many forms of algae can spring forth once the rock is introduced
into your tank. in favourable conditions, without too many herbivores around,
any Caulerpa amongst the forms
of algae can quickly become dominant. Caulerpa has three
basic requirements
for growth: a reasonably strong
current intense high quality lighting with a good photoperiod, and a substrate of rock or sand, which it quickly colonises using its adventitious root system. The current governs the form the Caulerpa assumes.
Caulerpa has remarkable regenerative powers, which allow a small drifting fragment to settle and quickly grow into a large expanse. In doing this, Caulerpa can take up large amounts of excess nutrients from the water column to convert into
plant material. In high nutrient aquarium systems, nutrient levels can be easily reduced by harvesting the luxuriant growths of Caulerpa.
Caulerpa also increases oxygen
levels in the aquarium and, during photosynthesis, reduces C02 levels;
pH is also stabilised by the same process and, in fact, can increase marginally under favourable conditions
Photosynthesis, of course, only occurs during the lighting photoperiod and one of the big advantages of the continuous around-the-clock refugium lighting used with the ecosystem method is that these benefits also become continuous and add to the stability of the water chemistry.
There is also evidence that in good lighting Caulerpa hastens the oxidation of catabolites. Phycocollides are also produced, which are large non-crystalline molecules that are often referred to as seaweed gums. These are similar to the ingredients used in water conditioners for aquaria and when introduced to the water a thin sticky emulsion results, which acts as
a coating agent.
These emulsions are called colloides, which, since they diffuse easily through living tissue, can protect fish from skin and gill disorders. Tests on aquaria filtered by the ecosystem method have shown that the system helps prevent and even cure lateral line disorder.
It's also long been known that marine algae, including Caulerpa, contain several substances that have a significant antibiotic effect towards fungal diseases and those caused by pathogenic bacteria. This perhaps explains why hospital tanks heavily planted with Caulerpa or other algal growth can quickly heal fish where standard treatments have failed. This is yet a further reason for the success found using the ecosystem filtration method in reversing head and lateral line disorders.