I’ve been watching the tank these past few weeks and looking at coral health. I probably should be keeping track of actual water changes, but I haven’t. The other night, I did one and reserved the water for a pre-water change and post-water change test comparision. Here’s how things shook out.

PRE water change:

Specific Gravity (refractometer) – 1.025
Alkalinty (Seachem) – 4.5 meq/L
Magnesium (Salifert) – 1470 ppm
Calcium (Salifert) – 460 ppm
Nitrate (Salifert) – approximately 7 ppm
POST water change:
Alkalinity (Seachem) – 4 meq/L
Magnesium (Salifert) – 1485 ppm
Calcium (Salifert) – 470 ppm
Nitrate (Salifert) – approximately 5 ppm
What I can’t quite figure out is why Calcium and Magnesium have jumped so much higher.  I’ve been dosing LESS with the C-Balance 2 part as pH has routinely been hitting 8.4 for brief periods, and have dosed maybe twice now with Seachem’s Reef Advantage Calcium instead.  That along can’t account for the drastically higher levels.  I’m wondering if either uptake has dropped off.  I say that, but some of the Birdsnests seem to be putting on a lot of growth and finally starting to color up.  Another working theory is that I opened a new box of Seachem’s Reef Crystals salt.  I wonder if maybe the formulation of the new batch is different than the prior batch.  If there’s inconsistencies there, a couple water changes could certainly be all it takes to dramatically alter the baseline chemistry of the tank.
I’ll have to keep an eye on things further.  Very, very curious.  I don’t yet have the coral coloration I want, especially out of the Birdsnests.  I’m also continuing to have a few bleaching issues with the various Favids in the tank, which I think stems from aggression between corals combined with an increased “bulldozer” mentality on the Lightning Maroon’s part – I consider that a good sign for the Lightning Maroon.  It was never a digger…none of my “male” Maroond dig.  The females however do.  Is this a sign that a sex change is underway?