I grow all kinds of things emersed with little or no nutrient input, I'm pretty sure my water is on the acidic side. If you look at my Wabi-k posts you'll see some of the stuff, I'm growing. If you are specifically adjust the water to be acidic etc then yes probably carnivorous plants would be the way to go. I'm having fun with Utricularia, U graminifolia is the most commonly grown species here on this site, I'm growing 2 other species as well, but have good luck with all kinds of other stuff.
If you want more specifics or have more information on your tank I'd be happy to give you more....