You might try feeding a little cyclopeeze. In my own (admittedly limited) experience with shrooms, shrinkage usually indicates they're not getting enough of something. My greenstripes are multiplying like aiptasia. I'm predominantly stony corals, with 250 MH, and I have green stripes clear up 3 inches from the top. My water params are: alk 3, cal 400, mh 1200, temp 80, sal 1.025, if that helps.