I think we really need a better handle on what the OP setup is like before we can suggest an 'easy' acro. While most acros have some basic similar requirements (eg. good flow, excellent H20, strong lighting, and proper chemistry), they can really vary in the specifics. From my experience, green slimers are pretty hardy but, in a recent tank crash, it was one of the first to go. Some of my 'difficult' SPS made it through without a scratch. Go figure. One thing is certain, if you don't have the basics down, no acro is 'easy'.