Better off waiting 4 to 6 weeks minimum to even consider any livestock whatsoever. Putting in a clownfish or 2 after 4 weeks is not a terrible idea. They are very hardy so they can handle any nitrate spikes, etc. if they occur. From there, clean up crew. Especially if you start seeing any algae blooms. I would add a combination of Nassarius snails (for your sandbed), Mexican Turbos and Trochus snails to clean the rock work. You don't need lots at first. Snails are actually one of the least tolerante things we put in our tanks. Any sign of ammonia or nitrate spikes can kill them off quite easily. be sure to acclimate them properly as well. As far as corals go, as long as you have low nitrates and no phosphates, you can start adding them. I would suggest waiting a couple months maybe but there is really no need to wait 6 months. Maybe for SPS, I would wait longer, but, LPS and softies will be fine.
Once you start adding fish, all ways go with the least aggressive ones first, to the more aggressive last to prevent fighting. 1 fish every 2 weeks is about what I follow when adding livestock. A good skimmer is a must here. The more fish you add, the more you have to watch for nitrates and phosphates. Running GFO, carbon, etc. will probably be needed down the road when your bioload increases.
Are you adding anything to help with the cycle? I would throw in a little flake food or pellets a couple times a week. You need to add a food source to get the nitrification process going.
