lol yeah i never cared if my o's rearranged their tank- i figure they are the ones living in it.. like everyone said, get some sand, driftwood and fake plants in there.. the fish need the stimuli and things to do..
i took out all the substrate just to help keep things cleaner. i might throw in some driftwood. i dont care if they rearrange things but i dont want them destroying the equipment. i shoulda kept my red devils. the constant fighting always kept them occupied