The peps will eat the aptasia and fish food that makes it to the bottom or the rocks. They are reef friendly. I'd go with the six peps for now. I put 10 in my 75. Never seen aptasia in 11 months.
Yur tank did finish cyling, right? Sounds like time for a few b/g chromis, peps, and a small cleaning crew. What's your outlook for inhabitants? If certain kinds of fish, bye, bye peps anyway.
"Life may not be the party we hoped for but while we are here we might as well dance!"