I'm trying to setup a new tank by the end of November for my daughter's birthday. The tank is a 29 gal. but I'm using a three stage filter and a venturi protein skimmer. Both are rated for 90 gal. tanks. I'll also be using a dual compact light ( 2 x 65w ) that has the led " moon " lights. Due to a limited budget I can't afford to spend another few hundred dollars for the live rock. I don't want that many fish, mostly inverts as she likes the more " weirder looking " creatures. Is there a kind of " dead rock " I can use and add " live sand " ? Please excuse my ignorance as I know nothing on this subject. Thanks for any help.