They are quite easy and can have quite a few coral types. Brandon is the master so will wait for him to post, but I do suggest no fish, just some inverts which are entertaining enough! It just makes it easier.
When running my jar I just bought two jars since they are so cheap, once you figure out how much rock you have can make the 2nd jar weekly with fresh salt mix and just pick up the whole rockwork and put in the other jar. Boom instant 100% change! I would do a once a week feeding a few hours before the w/c then it’s easy to export the remaining food. Just what worked for me.