AMDPhenomX4
Aquarium Advice FINatic
Do they reduce the nitrite level of the tank, keeping nitrates down?
I am not sure if you recieved a coherent answer,
Star Polyps are corals and not algae. They do not, to the best of my knowledge, consume nitrate (which I think you meant and not nitrite).
While I may be incorrect I believe what you are are referring to are species that are autotrophic and also help control nutrient export in the system. They don't consume nitrate but instead help in clearing the water column of nutrients before they can be converted into nitrates....