Good luck with the mandarin. If you got it to eat supplemental foods, it should be okay, but otherwise, doomed sorry to say. I personally think you have overstocked both your tanks, but if you keep a very vigorous maintenance schedule you should be fine, but make sure keep an eye on your params. JUST MY OPINION> OTHERWISE, the tank looks AWESOME!! Great work, I hope it all works out. How long has it been up?