Ok so Ive been told more than one thing on this. Here is the deal. I have a 20L tank that is doing great and has been up since feb. Has a 20G sump so id say the system is around 30G. I purchased a 75G tank with a 30G sump. I have dry rock and some dry sand. It is black sand though and I really like it compared to my white sand in the 20. I was thinking about mixing them but idk if I want to do that or not. Anyway my question is how should I go about switching everything over? Should I set the 75 up and cycle it before I put my stuff from the 20 in it? People have told me as long as I put all my water in it and rock and sand it shouldnt have a cycle and everything should be fine. I really dont want to loose any livestock. Ideas???