They are difficult to care for, however I have a green stokesi in a bb tank heavily skimmed and everything. The trick for mine is, I keep the goni right under a colony of gsp and they are nortorious for collecting debris and crud. Every other day I just gently blast the gonio with the crud leaking out from the gsp mat, and I can even see the tentacles taking in the "food". Mine is even budding. I have tried target feeding with no success. Sometimes they live and most of the time they wont. FME, the green variety are the hardest to keep alive. They also DO NOT like alot of waterflow and medium lighting. They can bleach overnight!
They are detritus eating corals as well as other types. I am still counting on it for long term survival, but it isn't showing signs of recession or brown jelly.