Im clearing my tank out of all my rainbowfish and my zebra danios and my fish that wont go well with discus. I was wondering if there are any oddballs that would work with discus..I am also keeping my hoplosternum thoracatum in there. Will there be any problems? The temp will be at 28 degrees celsius. The dimensons of the tank are 120 (L) cm x 50 (H) cm x 40 (W) cm. I was thinking maybe channa guacha..Would they be to agressive?