Please see post #47. I am directing those words to you too...... darn I posted again. This time, it's for real. 
Don't get me wrong brother. I love you. No joke. Welcome to MFK. I mean this. It's just that you and the other new poster is simply giving bad info. You are giving info based on what you are reading online. A lot of the stuff online is inaccurate. This is the best place to get fish knowledge in general -- with that said, I will no longer post on this thread. I will let others chime in. Believe me there are some here with some serious bichir experience & know what they are talking about. Learn from them. Listen to them. Take care brother.
If I wanted to look up to and learn from people I'd do it from those who don't currently have problems with females beating the **** out the males, fin nipping, fin ripping, rampages, advocate making fish aggressive, advocate overstocking, and turn a blind eye when people have psychotic fish and don't stop and ask why.
I am seeing allot of opinions posted here that seem to be from speculation, extrapolation from other fish, research from the internet, but not much from actual experiance. For example stating the potential 3' size of some bichirs, really anyone with much time keeping polypterus knows that is not the case with captive fish are really only a handfull of certain types in the wild.(PBB, Ansorgii, Congicus). Now I am not advocating the cramming of fish like sardines into your tank, but really the issue is with health stocking levels. Sub 12" upper jaws in a 75, easily 10 to 12 provided good filtration and water changes. Now would they be happy? How do you assess that? Are they happier in the wild with the risk of predation? Or captive in our tanks? Realistically any tank we provide is too small compared to their native habitat.
My advice to the OP. Go through the forum and lounge and look at others tanks, see different examples from the Heavily planted beaut of James F, to the large open tank of Hao and everything inbetween.
There are many examples of keepers with what some on this thread would considered overstocked tanks that has outstanding health fish with no aggression in the tank.
Most of all get a variety of opinions, do not look at one person as gospel. Research and see what actually works.
Good luck

Keep all the fish you want! Make sure your filter can handle the bio load and do water changes! They'll eventually stop growing if they have no more growing space. People overstock fish tanks all the time, I don't see why you can't. Beware! Most people on MFK are tank police![]()