I need some Help - Little to no growth

[Parker]

I need some help all, I just can't seem to get any growth out of anything. Where should I start? I've had some SPS in the tank for 8 months and you can't tell if they have grown AT ALL.

Some specs:
Ammonia - 0
Nitrate - 5-10
Phos - Undetectable
KH - 8
CA - 650 - Need to improve
MG - Can't find my test kit, I need to buy a new one
Salt - Seachem
RODI - TDS =0
Feed frozen and flake with garlic once a day.
I have zero algae in the tank, no hair, diatoms, cyano, very little film forms on the glass.

400W DE 14k - 2ea bulbs approx 1 year old 1ea approx 2 months old. The other two will get swapped out shortly, 1 this month and the last a month or two from now. ( I have the SPS under the new bulb in the sand bed )
Lighting is approx 6" from the water surface
No Actinic at this time
Lighting Runs from 4:00 pm to 10:00 pm
Temp - 79
Flow - 2ea Darts running two closed loops
Return - Dart
Skimmer runs 24/7 and pulls a whole bunch of crap out and is rated for well above my tank volume.
Running Carbon in a reactor.
Running Bio Pellets in a reactor.

Help me please! I don't want to buy anything more until I can get at least some growth..