hello i resently recived a rock from a member on the site with a bunch of palythoas exact kind i am unsure anyway i have had them in the tank 2 weeks or so and some of the heads dont open i think they all have been open at one time or another but probably 1/3 of them are closed up the water flow is about the same for the whole rock im using 4 t5ho the rock i probably 12 in down my specs are all good exept for my phosphates which i have been batteling there slowly headed down just looking for a little info on what to do to make all of them extend thanks