As some know I have a 625g FOWLR. I went through a “plague like” bacteria hit and lost some beautiful fish. Thankfully this is behind me and all is fine but I want to replace my Gem and purple tang. The dilemma is that I have established tangs in tank, amongst others, a 6/7 inch yellow and achillies. Previously they all got along because they were added at same time. I will employ all the tricks of trying to get it to work like using mirrors, adding at night,leaving lights off or using red lights for several days after intro etc. my big question is…..do I have a better chance of this working if I add similar size gem and PT? Smaller size? Or larger size ( this w/b difficult to find). Your thoughts appreciated. Any other suggestions welcomed as well. Wish me luck!