just added a foot long pleco. I have a 18 inches silver that kills every fish that I put in clown knife, red tail catfish, red devil all dead. would like to know if my new pleco would make it. I am at work right now and worried to find another dead fish tomorrow morning. my aro kills all his tank mates at night.
Plecos need some shelter, or the agressive tankmates may kill them by too much stressing, not only by agression. What type of pleco is it? Wanna see pics. With a shelter, the pleco is most probably safe with your arowana.