I think you are right on the ph, almost all the tanks I have kept have been a little acid, although the cachorros I have kept seemed a bit perkier with just a little salt the water did start out a bit acid. They do like cover plants, I had dwarf waterlilies and they would lurk under the leaves. I try to run all my tank lights through a dimmer switch to lesson the shock.
It sounds like you lucked out and got one of the less common species, they sometimes get shipped in with the others.
Of the three commonly imported ones only the falcatus (spotted) is from Peru. There are five others listed, one, the altus is like a small falcatus with darker spots, the abbreviatus has relatively large scales, the lacustris has a fairly heavy body, and the falcirotris (to 16") is more slender. I couldn't find a pic of the 10" microlepis.