They are good for large fish tanks because they will actually appreciate a little more protein in their diet than most pleco species. So not only do they need the veggies that most plecos do, but you can also feed them cichlids pellets and fish fillets every so often. Can be aggressive though, especially towards other species of plecostomus.
Mine pushes around a larger royal, 2 bushynose and 2 big hoplo cats. Nobody is allowed around his zucchini at feeding time