LPS/SPS Coral growth stopped!

[mattrez80]

I have run into an interesting dilemma... I have a 180gal mixed reef that has been up an running now for 2 years. For the first year and a half, I had decent growth with everything in my tank - LPS, SPS, and Zoas. Fast forward to today, everything has stopped growing. Nothing is encrusting, zoas are not multiplying, no new growth or splitting with my euphyllia. On the flip side, nothing is dying either which is good. I have not lost anything in the past 12 months.

Here are my levels:
Nitrate 4 ppm
Phosphate 0.4ppm
Alk 10
Calcium 452
Magnesium 1410
Salinity 34
PH 8.33
Temp 77

Flow:
(2) Gyre XF250 @ 60% LTC
(2) Jebao SOW @ 30% W1

Lighting:
(2) Orphek Atlantik V4 set to 6hr peak using BRS setting
(2) Orphek Atlantik OR3 150 Bars running 10hrs

Food:
Sustainable Aquatics Pellets daily
Frozen Mysis & Brine 2-3 times a week
Reef Roids or Coral Frenzy 2-3 times a week

I am happy that everything is colored up and polyps extended and no deaths... just confused why everything stopped growing. All additonal SPS frags that have been added over the past year look the same as the day they were added to my tank.

I am open to suggestions...

 

[MERKEY]

Looks like your phos is a tad high for growth...try lowering that slowly to.1 or .05 and see if that helps.

Things may have just gotten a little dirty over the 2 years.

 

[mattrez80]

Looks like your phos is a tad high for growth...try lowering that slowly to.1 or .05 and see if that helps.

Things may have just gotten a little dirty over the 2 years.

Great suggestion... best way to lower it? I currently have a 10 x 14 x 18 section in my sump full of cheato. Not to mention I am running a cup of BRS High Capacity GFO. I can never get my Phosphate under 0.4ppm. Could the daily pellets be causing that?

 

[MERKEY]

I'm not sure about the pellets...i have heard they are phos bombs but others say its a myth.

Knowing your gfo keeps phos around .4 consistently perhaps adding phosgaurd with the gfo to drop it to .1 and then continue gfo as usual to see if it holds it at .1 when you remove the phosgaurd.

Or more gfo for a short period...