I was not familiar with that filter (most people do not use HOB filters, especially if they have a skimmer) and it looks so high tech. :lol: I was like, "Oooooh shiny!" It does look like it is more suited for freshwater. But HOB filters and wet/drys are.
I am firmly in the camp that filters such as these are worse for your water quality than not having them at all. Especially since you have a protein skimmer. I'm not sure why you would need one.
Even with no filtration whatsoever -- no filter, no skimmer, you should be just fine doing water changes once a week or once every other week. If it was me, I would go with only the protein skimmer and do water changes every week or two.
Since you are using this filter (and again, wet/drys are generally frowned upon in saltwater), watch your nitrates carefully. They may start to go up. Like Ted said, you will have to keep it clean. That's the downside to these filters -- they end up being more work than they are worth because if you don't keep them clean enough they start to ruin your water. Most people recommend that you clean them thoroughly once a week.
If your nitrates start to go up, there's a sign that you need to get rid of it altogether and just have a skimmer.
A skimmer and live rock is really all you need. Especially in a small tank like yours. Many people with a tank your size don't even use a skimmer because water changes are all they need.
