Did you cycle the tank before adding the fish?
The damsel got stuck to a powerhead because it was dying, not because it was small.
We have some great artlcles about SW
setup. You just need to take the time to read them. I had a fw
tank for over 10 years before I started my SW
tank. There's a world of difference between the two. Water chemistry conisists of so many more items. The similarities are partial water changes are good and tank stability is the key to healthy inhabitants.
You might want to start with New Tank Setup List
and How to cycle your tank with out the use of fish
. (those are links, just click on them to see the articles)
Tell us more about your tank setup. Are you running a wet/dry or cannister filter, or do you plan on running it just on LR
and a protein skimmer?
Congratulations on your graduation and ....