I have a 45 gallon tank and I am in the process of setting it up for sw. It is going to be fowlr, no plans for coral. I have a canister filter, live sand, and some aragonite sand that I plan on using to make a 1 inch bed with. I want to start cycling my system soon and give it a week or two, but I do not have any powerheads at the moment, nor do I have a skimmer. What do I absolutely need to have before starting the cycle?