Reducing Nitrates

[Money pit]

Once you have your No3 under control, give a thought to adding a refugium with algae or an Algae scrubber. The idea of a fuge with algae, is to use a type of algae that is more efficient at using No3 and Po4 then green hair. I think most people agree Chaeto is the type to use.
An algae scrubber is a similar concept, but rather than using an efficient algae, your giving the algae a better place to grow other than your display tank. With a scrubber you use fast flow and lots of light to grow turf or green hair on a plastic canvas surface.
I've use both and they work equally well, both have pluses and minuses when compared to each other. With a fuge you can set it up as its own display, with all the creatures that eventually start showing up, it can be interesting, a negative is that it works best in its own small tank or container, unless you have an empty compartment in your sump.
A scrubber can be set up above the sump, but its not very attractive, so its best used where it isn't on display, on the plus side if you put a fan on the scrubber it works like the rad in your car, and will lower the temp of the tank. I have a scrubber on my tank, I'm on the 3rd floor of an apt bldg and the temp stays below 80 in the summer.