In the wild, Rhodactis mushrooms live in shallow, warm water. Before placement, check that your saltwater aquarium has a water temperature between 72 and 78 degrees Fahrenheit, a pH balance of 8.1 to 8.4 and a specific gravity of 1.023 to 1.025. Rhodactis thrive in medium water flow and light conditions. Rhodactis feed on free-floating microorganisms, so the water flow should be intermittent or alternating.
Rhodactis mushrooms feed via photosynthesis; the photosynthetic algae zooxanthellae lives within the Rhodactis and provides a symbiotic feeding relationship. Externally, Rhodactis mushrooms feed on plankton and larger organisms in the tank water, such as the miniscule marine phytoplankton and zooplankton. Supplemental foods include iodine, trace elements, brine, plankton and small meaty items.
In close quarters, Rhodactis are aggressive toward sessile invertebrates and may overgrow them. Place the Rhodactis mushroom away from other corals and invertebrates in the tank. In shallow tanks, Rhodactis mushrooms should be placed in the middle of the tank. In deep tanks, place the mushroom higher in the tank so that it has room to grow laterally. In high-illumination tanks, bleaching is likely; place your Rhodactis in the lowest area of the tank to avoid bleaching.
Rhodactis mushrooms vary in size based on position in the tank, the water flow conditions and the surrounding marine life. Small Rhodactis have three to four polyps. A medium Rhodactis has four to six polyps, and a large Rhodactis, six to ten. Rhodactis reproduce via fission or laceration, so overpopulation is an issue. A small polyp breaks off from the base or mouth of the parent polyp and grows to full size in several months.