Can I shut off one return

Still trying to get pool cleared up good after sitting for several years. I don't feel like my returns are moving lower portion of water like they should be. I angled the return going direct in pool at as much of a downward angle as possible. The question is, the other return just points directly on to what might be stairs, or dive platform at the deep end. It sits only about 6" inches below the water line. It was rippling the top of the water but I turned that one down as well but it just hits the dive platform. Can I safely turn this one off and use just the one for now or do I risk putting too much pressure on that one line? Thanks