I would switch from Phosguard to Phosban. Save the money on a new skimmer (the one you have is pretty good) and buy your own R/O/DI System. Other than that your tank is still fairly new and should just get better with age. I clean my glass in my two tanks every three days.
I've heard that ROWAphos is supposed to be pretty good. I would purchase my own RODI unit but I live in an apartment still.
I was reading the thread about dosing vodka. I think I'm gonna try that too.
I use ReefCrystals salt now instead of Instant Ocean. I don't think that would be an issue though.
ROWAphos and Phosban I think are the same thing. On the R/O just get the option where you connect to your faucet and run the waste down your drain. Fill up your containers, disconnect and put it on a shelf out of the way. Reef Crystals is a good salt.