We need more info to help you?
Tank size, lights used with size, how long have you had it, are you feeding it, are there other corals in the tank, how these corals are doing, etc.
I have a 100gal diamond tank, 75lbs live rock,2-3' flor lights and 1-18" power compact. I have green and blue mushrooms that are fine and 3 order leathers, all fine. I have the bubble located near the centre of the tank in about 9" below the surface. I have been feeding only phytoplex, 2 caps 3 times a week. I think everything should be fine. The bubbles open about half way.
From what info you provided I'd say lighting may be an issue...standard no floresents??
My green bubble likes fairly intense light...moderate current...excellant water ...and some meaty food(squid/mysis.silversides/shrimp/scallope) about once a week.....he is growing and healthy
Sounds like you have a nicely developing system....what are your readings for calcium/alkalinity/ph/temp
It's the lighting, with the lighting you have mushrooms and some leathers may do fine but you will have problems with a bubble.
I've found that even though most shops say bubble don't need great light... they do. If your lighting is not correct they will slowly shrink up and die. They also need to be feed some type of meaty tissue weekly if not a little more - depends on the size -.
One thing you can do for now is make sure teh buble is directly under the power compact light you spoke of. This may helo it survive for a little while longer.
However if I was you... and you want to continue to get corals that have higher lighting needs... I would upgrade the lights on your tank.
Hope that helps.
Thanks for the advise. It seems that it is hard to get honest advise at the fish store. I have moved the bubble right under the 55watt power compact at a depth of about 5-6". I hope that helps. Thanks again.
ijji... what your doing is fine because under both situatuions the coral is getting the nutrients that it needs: either through food or light.
Just most fish stored say that bubbles don't need lighting when that is false. If the lighting is on the small side that can be handled by regular feedings. But you have to make sure to feed them.
dmgreysquirrel make sure you also feed the coral and make sure not to cause bleaching by putting it to close to the light.
Also the coral will recover if it is not to late, usually in a couple of months
I would deffinalty check your calcium. I think that would play a big part in it not opening as well. Your calcium should be between 400 and 500 usually around 450 has worked the best for me even though so extra calcium could cause it to open better. Try taking some water to be tested or by a test kit. Oh yeah and if your calcium is low be sure to raise it slowly because too fast can stress corals out a bit. Just be sure what ever you do not to raise the clacium over 500 because too much calcium is very bad to leathers espicially. The excess that the corals cant use will form a crust on them and well slowly kill them.