Thanks guys. I didn't take the time to get the tape measure out when I was moving them, but think the largest is between 9-10" and the next two largest about 8". I'll be moving them into a new tank in a few weeks, so I'll try to get an accurate measurement then. I have a size 11.5 shoe for size reference..
Thanks, man. Been lurking a bit searching old threads lately getting ready for my new tank on order. It'll be my first time using a sump, so been studying up haha.