Melanie, although I agree with this and think that you'll be better off in the long run there are other ways to rejunvinate your tank. Here is a post which is a review of a talk I went to on "
Old Tank Syndrome"
Julian Sprung Speaking at WAMAS March 18
You may want to read it and then do some more on-line research to see if your tank falls into this category. If it does, then breaking the tank down and rebuilding is the best treatment.
Also here is a chronicle of a RS member who rebuilt her tank after being set up for several years. You may want to read through it to get some ideas as to the steps she took to rebuild a beautiful reef.
Lorraine's Rebuilding of 125 gal Tank
On a final note, don't get discouraged, this is a hobby that requires considerable work and delivers plenty of heartache, but the rewards are many when you can sit back and say I did that. You're in charge of a biological system and that requires constant learning and a continual commitment to make it the healthiest and most beautiful reef that you can. What has been recommended may seem daunting, but if you are to have the kind of reef that you see on this site, I'm sorry to say, you will have to commit to cleaning up your tank, one way or the other.