My RBTA isn't dong so well.....It hasn't blown up in about three days and it is losing color. It is just over 2 yrs. and in my tank for 4 months now.....about a week ago a piece of its foot ripped during a water change but I didn't see any ill effects. It still formed nice round bubble tips no nothing.....When do I know that there is no hope for it and take it out of my tank....Also, if it starts breaking apart will it release toxins or something that will harm the other fish and corals??? Please help FAST...Regards