I have about 60lbs of rock iny 90g tank and am about to add some more. With the additional rock I am going to need to glue them together. Is there a preferred glue and what if I mess up or want to change it -- hammer and chisel to break the connection?
And if you're willing to drill, acrylic rods, or threaded nylon rods - (available at marcorocks), and zipties as washburn says are all ways you can put it all together.
if you want to do some crazy rock work..to glue you rock use foam that comes in a can.and crush coral to the faom to make look like if its all rock..something like this