Looks like the ladies have you covered. I would remove the canister filter and the sponges/balls etc from the system - if it has been established for a year this is most likely where the nitrates are coming from.
In saltwater, your filtration is 1-2 pounds of live rock per gallon, live sand, and a good protein skimmer. If you do not have a skimmer I would seriously think about investing in one - they remove dissolved organics from the water, which is a primary source of nitrates. I see that you listed only 80 pounds of live rock. If you can, I would try to get a hold of either some additional live rock, or base rock. Since you already have some live rock, base rock can be used (and will become live in time)
Canister filters are really a freshwater technology, and do not work well in saltwater setups. That being said, they are handy to use once in a while for running various chemical media like carbon
I'm sorry you may have been frustrated by the amount of questions by others here, but in reality we do need a full system breakdown to help answer issues like this. If we only have half the picture we can't give you very good advice.
I would start by removing the canister filter / bio balls etc and stepping up water changes temporarily to see if you can get the nitrates under control. This may mean doing two water changes a week (or one larger one) for several weeks to get things where they need to be
Welcome to the reef, and dont forget to start a tank showcase thread