Questions about Betta fish maintenance?

Ok, First of all, Return the pleco now because they grow to 18+ inches and need nothing under a 80 gallon. They betta will be fine in the tank with some shrimp or snails. With a filter, I would do 10% water changes and never 100% because it kills all of the bacteria. Do it every 2 weeks. Don't turn the filter off at night because It would mean more cleaning and there is no need to turt it off. I hope i helped.