I have a new 90 gallon tank that I am setting up little by little and now I am down to my fijii rock. I do not intend to add fish anytime soon because as we all know...that rock is VERY expensive!!!! What I am wondering is will it be possible for me to fill my tank with water and just add rock as I can afford it (before buying fish of course) or will this somehow interrupth the cycling process?