I have a circuliar tank about 5 feet in diametre and about 6 inches deep. I am hoping to get some juvenile lobsters (roughly 3inches) and am looking for ideas on how best to divide the tank to keep them seperate
The type of material and method of construction depends on your preference, and there are many possibilities. I will mention two common materials:
Plastic egg crate is easy to work with, but you may want to use acrylic if you want something more attractive. With egg crate, you can use plastic ties to loop thru the openings. Same for acrylic, and you can even cement it to the tank if it is also acrylic.