I had a 36 gallon tank as my first reef and my set up was almost identical to yours.
I found that when I had a sponge or floss or anything like that in my cannister I got Algae galore and high nitrates, even after large water changes.
As soon as i took all the media out and just packed it with LR rubble, my tank became very self sustained.
only my experience and yours of course may vary.
cheers.
If you're getting Algae blooms, add some snails...
It's always debatable as to when you should add the cleaners but I have had good results adding them slowly, maybe not all at once.
I also don't like hermits too much anymore, really fun to watch but expensive in their snail shell stealing mandate.