Beefheart can lead to dietary deficiencies. If you feed it, make in homemade, as store bough stuff is almost all beefheart and no good. I will not dispute that is leads to excellent growth in young fish, but I will never feed it to mine. It is high is protien, but lacks pretty much all vitamins and contains a few antivitamins. Me an Mike were disputing whether or not it caurses fatty liver disease also, due to mamillian protien being contained in it, but we have not yet concluded that discussion, as I cannot find the paper I read a year or so back that supports my side. All I will say is that some, (myself, Diter Untergasser and others) believe that Beefheart is a poor choise of food. If I say it
is (rather than I believe it is) a poor choise, I'll start an argument, but that statement should be read as such
Fish feed a staple of Beefheart in a varied diet can supposidely aderage 10 years of life. Diter Undergasser reports 35 years to be the adverage lifespan of his fish in one of my reference books, and he does not offer Beefheart to any of his fish. There is nothing else in the care of his fish that explaines the drastic lifespan difference jumping out at me when I compair his methologies with those of other keepers, other than diet. For this reason I don't offer Beefheart to my fish.
If you do feed Beefheart, make your own, and only allow it to make up 10-25% of the mix, using other foods to make up the rest. Homemade beefheart requires a fair bit of work and IMO isn't worth it.
Mine are fed Discusin dried pellet twice a day as the staple, with two to three feeds of Tropical Quintte also daily. I got good growth from most of my fish, when combined with twice weekly 50% waterchanges, but still believe at least one of my fish is stunted

Untill about 4-5inches though, 50% daily waterchanges should be considered minimum.
To me, most of you fish look OK. Most have good shape for their age and also have good colour IMO. Discus don't look like discus untill the 3-4 inch mark IME. To me those fish look normal

Mind all the juvinile discus under 4 inches that I've seen are poor quality when adult, so I'm not shure I'm fully qualified to make that statement... I bought mine at 4 inches for that reason...
HTH
Rabbut