Be prepared for the hippo to get ich, they all do I think. Look at lowering your salinity to deal with it 1.009-10(gradual from LFS water to there try no more then 3 points a day). Give the guy a boost for his immune system with garlic and selcon with his nori/mysis. Then 3 weeks minimum after it goes away you should start to raise the sality to normal and you ought to be good to go. If he actually doesn't get it you are really lucky.