Live sand and Live rock are great filtration methods but really should be combined with a skimmer to remove excess proteins. Without a skimmer, plan on doing lots more water changes to make up the difference. Adding another 10-15 pounds of live rock would be beneficial as well. Without a skimmer, you're going to have to keep your fish population very light. Also, don't plan on being able to keep any SPS or many LPS in your tank. Soft corals will do well in the nutrient rich water you're going to end up with because of no skimming.