Will the mandarins get along?
Overall, everything is doing fine. The mating of the two mandarins doesn't appear to be likely, at least for now. The green Target is still very aggressive toward the orange female Target Mandarin. She continues to seek food, but the male will suddenly swoop in with a burst of speed, his dorsal fins fully extended -- and she darts into the rockwork for safety.
For the first few days, I saw white spots on her back, which I'm assuming were bites from the male. Perhaps she scratched herself during one or more of her quick escapes. Today I saw most of the white is gone, which is a good sign.
And the best thing I noticed is that I can't find any more flatworms (red planaria) in my 55g reef any longer. The Six Line Wrasse and the green Target never ate them (as advertised), but the orange one apparently is taking care of them! Jokingly, I wonder if perhaps she is another green Mandarin, but by eating red planaria, she appears orange? LOL
I got two Mangrove plants today, which I inserted into my refugium. They can help reduce nitrates, but I'm adding them more out of novelty than for a solution. The greenery is not really visible as it is 24" tall from roots to the newest stem, but as there is 4" of space between the stand and the wall, the Mangroves will get light both from the refugium's light source as well as the main lighting.