landmineyouth said:
15 watts of light is not close to enough for corals, shoot for 3 to 5 watts per gallon
3-5 is ok for soft corals like mushrooms. But you need to go higher for sps corals like 5-10 watts per gallon. However, being new, your best bet is with lower light corals such as leathers, xenia, open brains and the such. .
Also, the film on top is most certainly not algae. Most likely it's protein film. The reason we run skimmers is go get rid of that. Keeps the corals healthy as well as the fish. Try doing small water changes frequently to reduce that, or pop a skimmer on the tank. Some of the hang on back filters are decent. Not great, but decent. Try running some carbon in the tank, however, if you've got a film the carbon will get used up quickly and you will have the same problem again.
As far as stocking the 10 gallon, since it sounds like you've got lots of rock in the tank, you may only have 5 or 7 gallons of actual water in the aquarium. In which case, I wouldn't put any more fish in that tank as it sits right now. However, when you go to the 47 gallon, you can add more fish. If you like the damsels add some more, if you want to try something new, Cardinals are an excelent suggestion. Clown fish are really cool, but are absolute a-holes to you when they get established. Most anyway. I had the coolest maroon clown ever. However I also had cinniamon clowns that would attack your hand on the skin between your fingers where it's nice and soft and death roll like a croc. That fish was the most aggressive fish I've ever seen. You couldn't put your hand in the aquarium without getting attacked. 100 gal tank at that. Also, pigmy angels are pretty sweet little fish, and for the most part really hardy.