I'm making an overflow with specimen cups, I bought the cups from my friend's mother's pet store because she's not selling fish anymore. Problem is, I bought 2 small cups before realizing that the design I'm going for requires one small (for the inside of the tank) and one large for the outside. Can I still make due with these or will the outside of the overflow....well, overflow? I have some sheets of acrylic that I'm cutting up to lower the outside box and get a stronger syphon. I'm thinking maybe if I have enough drainage in the outside box that it'll be alright. But I need some input before I finalize this thing and get my sump finally running.