Monti with Fading Edges / Growth Plateau on Amino acids

[Tennyson]

Hi All,
- My beloved montipora hasn't grown since 3 weeks ago.
- This coincided with starting acropower 1 week before at 5ml/day for a 160 gal (Instructions suggest 5ml/25gal/week). I remember most of my corals responded well to acropower except for this one monti which had a surprising hault on growth.
- Splotchy/faded color around the edges began 2 weeks ago(see pics).

As soon as I noticed the fading edges, I rearranged its position, improved random flow from all sides, and dimmed LEDs to lowest setting. Its been 2 weeks with no changes.

The splotchy edges are not new growth, which looks slightly different. The pic with the banggai shows it 2 months ago when it was growing to make the distinction. My green monti is also happy.

Params:
Temp: 77 F
Ca: 450
Alk: 9
Mg: 1275
pH: ~7.8
NO3: 7.5
PO4: <0.1ppm
Salinity: 1.024

Any suggestions are welcome and yes this might be nitpicky

 

[Big G]

following

 

[Tennyson]

Just remembered, I was on a trial bottle of KZ Aminos: LPS Formula before starting Acropower SPS Formula. I waited a month without any AAs before starting Acropower, but I also wasn't running carbon at the time. Is it possible I had residual KZ Aminos in the water when starting Acropower?

My guess is the switch from an LPS to an SPS formula disrupted recent growth, and now the coral is struggling with the new water chemistry. Going forward it would be worth knowing what distinguishes an SPS vs an LPS amino acid formula. Maybe I'll cut back on the acropower to start?