I am THINKING about trying a salt water tank. I have had fresh water for quite awhile, but don't know anything about keeping salt. So I want to study.

My first question is can I use my AQ110 HOB filter on a saltwater tank? 2nd question.....is a 30 gallon big enough for a newbie to start with?

The AQ110 can be used for your salt water tank, but you would want to clean that sponge out weekly or eventually invest in a protein skimmer and get rid of the filter altogether.

The thirty gallon would be a great tank to start with. My first tank was the standard 29 and it was easy to keep balanced and the temp from fluctuating.

yes the filter would work, and you would need a protein skimmer. A 30 gallon is probably a good start but dont add more than 1 or 2 fish, saltwater fish are very sensitive and need lots of space. I did my research lol, cause Im getting a saltwater for christmas The fish are really pretty. For a 30 gallon I would recommend percula clown fish or small damsels such as a 3 stripe, those are also the ones I want! They are so pretty!