The one is more outgoing than the other. i wouldn't recommend them too much without a lot of cover and plans to get food down to them. they also might get skittish with the odoes when they grow bigHow shy/skittish is your knife? This tank is in a high traffic area. I might just go with a knife and plecos as bottom feeders unless I can find something that I like better.
I plan on getting more wood and some floating plants as well as more knives to try and increase how much i see them.
