You mentioned earlier you saw no signs of disease. Of course if you put another larger fish in the FH will attack it.If he has parasites I dont want to put another fish at risk. This flowerhorn is an aggressive flowerhorn. When I was acclimating him in one of my tanks he was trying to attack my Oscar's (who are bigger than him) through the bag. I dont want to risk killing another fish just to save another. It wouldnt be fair or kind to the other fish. I also just medicated the tank so if I put in the fish I would be putting it in a medicated tank when it doesnt need the medication. Fish are capable of living by themselves. Especially flowerhorns. Which are actually suggested to live alone. If I have to lose him I will but I'm not going to kill multiple fish.
What temperature did you decide to target? It's a good idea to increase gradually.Of course and I appreciate the suggestions. But he is still within the first 6 week quarantine time. And boredom wouldn't kill him. I just wanted to show my train of thought on adding in more fish. I did put up the temp. I'm putting it up 2 degrees a day so I dont add more stress. As I already said I also put in the general cure in case theres an internal parasite I cant see. The foods I have tried are api pellets, topfin pellets, and hakari gold. The treats I've tried are omega one shrimp, bloodworms, and tubiworms. He reacts the same to all of them. I have thought about the garlic guard and I am going to look into what it does and how to get it. I dont do anything with my fish without researching first.