When I got my first BN plec about.. 1.5 years ago, i didnt even know you have to give them alge tablets or veggies, i just thought it ate the alge on the tank and what everfood floated to the bottom..
It was only a few months ago when I joinmed here that i realised what they really needed.
He was fine living on 'normal' fish food, but i did notice a growth spurt once i was feeding him 'real pleco' food
My pleco is still alive to this day, and thou he doesnt get veggies very often as i always forget to take them out of the tank before they start falling apart, they get Alge tablets once a week, maybe twice.
thats my experince, just thought you'd like to know.