Having trouble with SPS

[510reefer]

Hi! This is my first post here on R2R so please bear with me as I try to explain my issue. My tank a Red Sea Reefer 350 has been up and running for about 9 months. I have mostly been adding LPS over the past few months and just recently started to try out a few SPS pieces. I have had no problems with my LPS and have seen good growth over the months. I have not had any luck with a couple pieces of SPS.

A little bit of background on the equipment I am running; 1 Kessil AP700 light, 2 mp40s, bubble magnus c5 skimmer, brs dual reactor running GFO and Carbon. I run the AP700 mostly on the blue settings and at most 75% intensity. The mp40s run in nutrient transport mode in anti sync mode, the master is set at about 50% power.

On the green monti in the picture below the edges are starting to turn white and the center seems to be turning brown. I tried my best to get a ok picture. This is the second monti piece that i have had this issue with. I know my tank is still relatively young but is there anything else I should look into to help prevent the issue I am running into?

Here are the current parameters of the tank:
Nitrate 2 (red sea test kit)
Alkalinity 8-9 (red sea test kit)
Calcium 450 (Hanna tester)
PH 8.2 (red sea test kit)
Magnesium 1290 (salifert test kit)
Phosphate .10 (normally it is 0 or .02) (Hanna tester)

I do 20% water changes every 2 weeks.

Here is what I currently dose:
20 ml of B-ionic Alkalinity daily
20 ml of B-ionic Calcium daily
6ml of Red Sea NO3PO4-x every 3 days
Red Sea Reef Energy 10ml of A and 10ml of B

Thanks in advance for the help!

 

[CodyRVA]

You have a range for ALK of 8-9, while this is a a solid "range," consistency is much more important than hitting that magic number. If your parameters aren't stable day to day, that could very likely be the culprit.