To keep my alkalinity, calcium, and magnesium up, I dose the
Randy Holmes-Farley two part solution (Recipe #1) found at
http://reefkeeping.com/issues/2006-02/rhf/index.php I have a ton of Dowflake if you'd like to get some from me at the next meeting. For the magnesium, I currently dose a mix of Epson salt and Seachem Reef Advantage Magnesium.
For water changes, I only change about 8% per month, but using ozone and small daily feedings help to keep the water clean.
I use 10k XM bulbs, which have a much higher par value than most other 250w bulbs. The bulbs are too yellow for my taste, so I supplement them with 2 VHO superactinic bulbs.