The tank is still struggling a bit. I still have a couple corals that are STN'ing that have been this way for some weeks. Recently, the A desalwii has lost the flesh off the tips for some reason. Interestingly, the frag I have of it from a branch I broke, which is on the sand has also lost the flesh on the tips, though it is a couple days behind in reaction. The desalwii seems to be the only piece affected by whatever it is. Things I changed immediately before this reaction are: I added a fan to the ATI fixture (the ATI fans aren't working) so now the fixture isn't auto-dimming from overheat, so they are getting a lot more light (still only 250 PAR to this piece), I added a bag of carbon to the sump (I removed it now), and I upped the Sodium nitrate dosing from hovering between "0" and 0.5 ppm to 1-2 ppm. The last alk swing was late August where alk went down to 6.3 dKH from it's usual 7.3-7.8 dKH. I hope it doesn't turn into an STN or RTN case, and the tips recover.
I did notice that I've been getting a significant pH swing overnight. Just before lights on the tank sits at 7.9 and at the end of the photoperiod it's at 8.3. Maybe this is the problem. I'm currently dosing kalk every 30 mins 24/7, maybe I'll start dosing cal/alk during the day and kalk at night.
Params over the last month:
Cal 410-415 ppm (Elos)
Alk 7.3-7.8 dKH (Hanna, Salifert)
Mg 1300 ppm (Salifert)
NO3 "0" - 2 ppm (Red Sea, Salifert)
PO4 0-6 ppb (Hanna)
I picked up some Oyster Feast and have started adding 3-5 drops every evening just after lights out. I ordered Acro Power weeks ago, but it hasn't shown up at the LFS yet. I turned the skimmer down awhile back, so it's skimming dry as a popcorn fart.
I'm considering adding Brightwell NeoPhos to help keep a PO4 reading. Does anyone use this product?