Beautiful tank. I'm also on the 3-4 months water change schedule, but that's due to my work and the fact mine is not automated like your's. MAD JELLY about having such a pain-free water change system my friend. I wish I had the space to set one up but my wife would kill me if I took over the closet to do so.
A fellow reefer friend was just asking about my toadstools in my mixed reef and whether there would be chemical warfare between the toadstools & the sps. Apparently, looking at your healthy reef tank, it is not as big an issue as some have claimed.
Anthony