Way to big they can grow anywhere between 8-15 inches depending on the type. If you are after a small plec then you could look at a brisltenose 5 insor a Clown pleco 4 ins but with that size tank you would oonly be able to fit one.
What are the dimensions of the tank? If it's 36" long, you may be ok. L018 nuggets grow to about 6", so would have 5x adult size of swimming room in a 36" tank (which is pretty much the minimum).
14Gallons is only big enough for rubbernosed bulldog plecs or clown plecs and the odd pekoltia... Not even big enough for a Bristlenose really unless you have hardly anything else in the tank.