In my past 4 yrs of experience with my MI, I haven't noticed its health to be directly related to the growth of the streamer. This fish certainly enjoys large body of water and mine prefers to be one of the largest fish of the tank. I had to feed it 4 times a day during the first year or so, and now about 2 times a day. He used to only eat NLS finicky pellet, but now is okay with formula II, regular NLS, frozen krill, clam, mysis, and brine. He once got sick and was covered with ick. It was a FOWRL tank so I dosed it with cupermine, which quickly resolved the problem. Judging your MI wrt to the flame wrasse and what appears to be MP40 tells me he is about 4". If it still has ick, your best bet is to move him to a QT that's as large as possible. I now personally keep a 90 gallon QT just in case if a big fish gets sick. Good luck.