In response to your question:
My tank is 80 gallons, i have a fluval 403, a filstar xp3, a turboflotor 1000 hang-on, a lifeguard fbf 300, and 2 aquaclear powerheads for filtration. I also have 30 pounds cc and 60 pounds live rock. My tank has been set-up for about 6 months. The inhabitants are 5 massive turbo snails(2inches), 1 niger trigger(3 inches), and a violtans lion(5inches). I test my water once per month and this month the water was 0 ammonia, 0 nitrite, 140+ nitrate, and 8.2 PH. I just did a 30% water change and rinsed out my filter media in tank water. I also cleaned skimmer and have toned down feedings over the last few days but it is still high.
My nitrates have always been high but not this high(around 50).
thanks for your help
Jon
P.S. I am going to do another test tonight after the water has settled from the water change and see if it is ay better.