Hello everyone ! It has been a long time since I created this topic.
First of all, I want to thank you all for answering my questions, MFK is realy a wonderful place, with wonderful people !
I've returned here to announce that my dream finally came true : I have a nice community tank with predatory fish. It's quite a sweet story in my opinion, so let me tell it shortly.
6 months ago, a friend of mine running an aquarist shop stumbled upon several newbies giving away species they bought without proper research, and causing some problems. Among them were classics like the red tailed shark and the clown loach, but also some predatory fish like a rainbow snakehead, two hujetas, two amazone leaf fish and four freshwater butterfly fish. So my friend decided to take these fishes with him in order to sell them to people who could keep them.
But there was a problem : no one wanted the predatory fishes, and lacking space, my friend had no choice but to keep them in very small tanks with no decor, which was fine as a temporary solution, but not on the long term. He only had one solution, calling me, as he knew I had a beautiful empty tank ready for use, and I still haven't decided what to put in it. The deal was simple : I would keep these fishes, and watch them closely. If there was any problem with one of them, I would give it away as soon as my friend would find someone with a suitable tank to house it.
And so, 6 months passed. And you know what? They're all still living happily and peacefully in my tank, greeting me every day with their amazing behavior, and their stunning beauty !
I thank you all once more, and wish you a lot of pleasure in this wonderful world of fish keeping !