I have a BN, and he is a very good algae eater (but he must be fed veggies/fruit, wafers, pellets, of course), has great personality too. He doesn't eat plants, but he uprooted every stem plant I had (about 10), the larger plants I have are fine. My 3 year old picked a BN over ottos, LOL. Big plus is he ate most of the baby snails that hitchiked in on the plants.
Congo tetras are African, not SA, btw.
I have a 55 gallon with- Bolivian Rams, Angelfish, BN Pleco, Cory Catfish, Flame Tetras, Cardinal Tetras. I LOVE my mix, except for the Cory's. Not really enough activity, I got pandas and 2 out of 6 died within 2 weeks (2 of the 3 fish deaths I've had) and with the Rams and BN I have too much activity at the bottom. Some are all about Corys, me not so much.