From what I observed, yes...the heads of the polyps start to get closer to the surface making the tips of the bumps appear lighter and more bulbous. You can try putting some phytoplankton once to see if there's a reaction. Then wait to feed them again when they do open. More like teasing them out.
Carbon should only be run in a reef for a week once a month with reef grade carbon. Reason being, carbon is said to absorb some of the essential trace elements from the water, so running carbon 24/7 can deplete the system and make a need for constant replenishment.
Get a skimmer or refugium. Corals can get 'choked' from proteins in the system. A skimmer mechanically removes proteins whereas refugiums biologically break proteins down. Some people like to use both. A little Prism skimmer should do fine...or a CPR backpak 2R. I have an 18 gallon with just an oversized refugium on it...Ecosystem 40. Made to filter up to a 40 gallon tank and fits perfectly on the back of any 10, 12, and 18 gallon tank. Siphon starting the tube that leads to the overflow is a pain sometimes, but the refugium unit has proved very successful.
A skimmer and/or refugium will also help control nitrates a lot better than just a regular filter alone.
You can check out photos of this 18 gallon mini reef in my gallery. Just click on the link
We, as a people, know so much more about outer space than we do about our own oceans. This lack of knowledge can very well spell the dangers that lay in wait for us.
The oceans surely would swallow us before a rock comes down to smite the planet of it's life.