plate coral ?

[clevebill]

i have a short tentacle plate coral and it has a brown rim around its mouth area. it never had it before and i notice the tenticals dont get that big anymore when i first had it.it still eats and today i watched inflat itself and it did poop.i was just wondering if its on its decline or kinda normal.what kind of flow do they thrive in stong, medium, or slow.


thanks ,bill