I think you may also be able to squeeze by without a skimmer, however a skimmer AND water changes can't hurt. Besides a skimmer is better than no skimmer. In a small tank and such a small volume of water, anything that skims anything will only benefit your tank. I've heard a lot of good things about the aquaremora, but I've had luck with the cpr bak pak and the seaclone100. The seaclone100 isn't as bad as people make it out to be IMO. it works for me =)