54 Gallon Bow-front reef tank, I need some advice/suggestions

[ReefGirlSara]

I want to add some variety to my tank. I haven't had the very best luck so far, and I don't really know what I'm doing wrong (or right for that matter). When I got my tank it looked like the first picture, and now it looks like the second picture. The candy cane corals are doing great, the green open brain is ok, and the yellow tang is the only original fish. The other fish all died of ich after a long move.

I would love to know if anyone has some advice on how to get these star polyps to come back. I really liked the color they added. When I first got the tank there was too much of it, now it's almost gone. Also, the xenia shrunk up until they disappeared altogether, and the big beautiful anemone (not sure what kind it was/is) now looks like the last picture. I got the new GBTA about 2 weeks ago and it seems to be doing ok. I feed it 1 lance fish every week.

Also, I would like some recommendations for some nice looking, easy to raise LPS corals, that I can get for not too much money... Don't worry, I won't add anything until I get my tank completely stable.

I dose Oceans Blend, and these are my water parameters right now:

Calcium: 450
Ph: 8.2
Phosphate: 0
Nitrate: about 10-15 ppm, I am doing water changes to lower but it doesn't seem to go down. I've never had a nitrate problem at all until the last month.
Temp: 80 degrees

175 W MH with 15,000K Iwasaki bulb, and two very little 20" blue actinics, I'm not really sure what they are, the LFS sold them to me for about $15 each.

[Sk8r]

I'd say nitrate is a problem. What's your skimmer [brand] and are you using a filter [known problem]?

[ReefGirlSara]

The brand of my skimmer is SeaLife Systems, I bought it from my LFS and it was pretty expensive (somewhere around $150-$175, I don't remember). I am using a wet/dry with the blue bio-wheels, with a blue and white filter pad sitting on top of the carbon bag on top of the blue bio wheels. I change the blue and white filter pad at least once a month and the carbon every other month. The filter pad (I'm not sure what it's really called) is about 3/4 of an inch thick and very light weight, they sell it in all the LFS's. I don't know if this is what I should do, but it's what the guy I bought the system from was doing and it's what the LFS told me to do, so I just kept doing it.

The tank was set up for about 3 years when I bought it in March of 2006. Up until about 1 month ago, the nitrates were zero each time I tested them. However, the problems with the xenia and star polyps started long ago, and the xenia died off completely last December.

[ReefGirlSara]

Oh- forgot to mention, the skimmer, even though the LFS said it would be overkill for my tank pulls out next to nothing. I mean really, next to nothing! Maybe a teaspoon in a week, if I'm lucky these days. I'm running it as wet as I know how.