Alternanthera Bettzickiana. Pink water rose is its common name. Cant say Ive ever seen it grow in an aquarium and dont think it does well underwater. more of a bog/marsh plant.
They arent the true "peru angels". The just angels guy on trademe was telling me HFF said they could get them but they would be $150 each in which he declined the offer. I havent seen the true peru altum in NZ