i get a large/long cucumber and usually cut it in half or into thirds and then slice the sections down the middle and add weights to them to make them sink into the tanks. My largest common pleco can easy get through one of these large peices in a single night, i don't think common pleco's will overfeed on cucumber, once they've had enough they'll leave it alone.
When i remove the old slice of cucumber should i add another one or i should put another one after 1 week?