Oysters are filter feeders. They like high plankton count water. In most home aquaria, they'll filter the water and starve. I've seen them used as disposable filters to handle algae blooms in a couple of tanks. Takes 3-4 oysters a week to filter all the algae out of a 100g tank, and without target feeding, they will starve very quickly. They like nitrates because nitrates are food for their food. The parameters considered ideal in most home SW aquariums are not suitable for them.
Want them to filter your tank to improve water quality, they can do that quickly. Want to keep them long term, not easy. Want to keep them for 10 years and have them make you a few pearls, Not going to happen. There is a reason cultured pearl sellers use leases offshore. The water params they need to thrive are just not easy to setup and keep right in a home aquarium. Not worth the effort imho, but hey if you wana try it, go for it. Just dont count on them living more than a year at most, with target feedings.
even in the tanks where they were used as filters for algae bloom, they werent in the DT, because they couldnt get enough flow. They were placed in the Sump.
