The Lavender Mushroom is also called the Purple Hairy Mushroom. It is another member of the Rhodactis genus that is easy to care for. They are similar to the Green Hairy Mushroom Rhodactis indosinensis, yet different. This can be confusing since both of these mushrooms are often just simply called 'Hairy Mushrooms'. The Purple Hairy Mushroom grows only to about 3 inches. It does not grow nearly as large as the Green Hairy Mushroom which often will grow 5" to 7" in size. They also need a lower level of light. Appearance wise, they are also quite different. The R. rhodostoma have much more developed marginal tentacles. Its tentacles are branched and spaced apart, which makes it look like a cauliflower arrangement. It also comes in purple, so this is the species you will probably be getting if it is labeled "Purple Hairy Mushroom" rather than just Hairy Mushroom.
Water Flow and Lighting
The Rhodactis rhodostoma is easy to care for but needs low lighting. If the lighting is not their liking, they will fail to thrive and/or shrink. They can easily be brought back by changing their position in the water and by extra feedings. As far as water movement, they prefer low water velocity, but will do okay in a moderate flow as well. Lighting can be Power compacts, T5's, LED's or Metal Halides. All lighting can grow Mushroom Corals as long as the proper level of light is provided. If a Par meter is available the appropriate lighting level is anywhere from a Par 50 to a Par 120. For lighting spectrum use between a 14-20K color spectrum for your bulbs for best coloration. Rhodactis rhodostoma are easy to aquaculture in captivity and is very easy to propagate in any home aquaria, which can contribute to preserving the wild populations. Just keep it well fed with small pieces of fish and crustaceans will cause mushrooms to multiply quickly.
All mushrooms are semi-aggressive and require adequate space between themselves and other corals. Placement can be any where in the aquarium as long as it receives adequate water flow and lighting levels and leaves enough room around your corals that they have room for growth without infringing on another corals growing room or lighting.
Diet and Feeding
Mushroom corals receive the majority of their nutritional requirements through the process of photosynthesis, which simply means their lighting creates symbiotic algae called zooxanthellae in the body of the coral which provides its nutrition. We do recommend providing supplemental food such as micro-plankton or foods designed for filter-feeding invertebrates.