Hi everyone, Apologies in advance for the long post. Despite registering with the site back in 2012, I'm still considering myself a newbie as I've been dipping in and out of the hobby for a few years now - as will be noted from the number of messages I've posted to date. I have however recently moved house (July 2017), and in doing so have bought a larger tank in the hope of establishing a Marine tank. My past experience has been completely fresh water (100L tank) and I'm dreading the change to Marine - so much so that I've had an empty tank for 6 months now. My local garden center were selling off an ex-display tank with a mishmash of pipe work. So now, I am the proud owner of an AquaReef 275 with sump (which I think is about 30L). Tank dimensions being 70x70x70. The tank came with a protein skimmer, 4x T5 Lights, and 2x Heaters. I've additional bought; - Return Pump (Reef-Pump DC Aquarium Pump 4000) - Filter sock - Refractometer If I'm honest, I'm feeling a little overwhelmed with next steps and the options available to me. I would be grateful for advice on what I do next. Here's what I think I need to undertake: Buy egg-crate to place on base of tank. Buy wave maker fan - need to decide what would be an appropriate fan. Do I need one or two? Replace sump bio-balls (which came with tank). But not sure what to replace with, I've been told I could use Live rock. Live rock v dry rock; I believe I need about 1lbs for every 10L of water. So give or take about 25lbs of rock due to water displacement. I need advice on whether I should put rock in the tank or within the sump. I'm leaning towards pre-sculptured dry rock in the tank, and having some live rock in the sump. Sand - Need advice on how much I need. I'm guessing the amount is more of an aesthetic requirement to ensure there's sufficient grounding for rock etc. But question whether sand should also go into the sump, not sure what the (dis)advantage this would have. Sump - does this need lightling? Currently it doesn't but is housing 2x heaters, return sump, protein skimmer, and bio-balls (which will be replaced). I feel a bit silly writing this, but the next big fear is water. I don't intent to buy a RO-unit immediately, and will likely arrange to buy circa 300L of water from local fish store. This alone worries me as will require several trips back and forth. However, should I undertake a test run of the tank with tap water to make sure everything is working? Am I missing anything else? I'm guessing I'll additionally marine water test kit, and all this before I decide what type of fish set up I'd like. I'd like a community tank with Clownfish, Gobies, Fire Shrimp, but I would also like a Dwarf Lionfish. Anyone have recommendations for a first time Marine owner? Grateful for advice and help.