My guess is some stores are more conservative than others. In the old addage "nothing good ever happens in a reef tank"-- The one person I met at a lfs in Calgary that said that meant that the tank would not be fully stable till then. Perhaps this is what that person meant also. However just because it isn't fully stable doesn't mean you can't start adding things. Really you can't go wrong if you go slow. A shrimp, snails, cleaners and such

Sounds like you are doing a great job, and four months of waiting, you deserve to see something move in that tank. I applaud your patience!!
