Hi , new to group and discus . I have had African cichlids for many years and have moved house . I have a 5 x 2 x 2 ft tank ready to set up and thought I would like a change. I was thinking of just going tropical but have always liked discus, are they difficult? I also have crushed coral for the substrate from my previous tank, can I use that? I am just starting my research journey and thought I would start here