You Pleco's are not good to be in your tank so you should try to rehome them.
2 Reasons:
1. The big one will grow much bigger and outgrow your tank very soon
2. The Pleco's are tropical fish
If you get rid of your Pleco's then you could get some Borneo Sucker/Hill Stream Loach's which are coldwater. They do like a strong filter flow however they are fine with a calmer one. You may want to get more than one for your tank size.