Most nano reefers don't run skimmers. Not really feasible if you have a small set up. Just keep up with very regular water changes, as that's going to be the only form of nutrient export you will have (unless you're running an algae scrubber or refugium, but if you're doing that, you might as well throw a skimmer in that sump!). So just be diligent in your maintenance, and you can keep all sorts of coral.
As a matter of fact, there's a whole host of 10 gallon nano-reefs currently under construction, and I don't believe any of them is running a skimmer. I know I'm planning on doing an SPS heavy nano and I'm not running a skimmer on it. I may live to regret that decision, but that remains to be seen.
Anyway, good luck!