Recommendation on my tank?

[mstrassbur]

I have a 75 gall main tank with a 30 gallon sump thats been running for almost a year now
lights are 2 DE 100w 14000 and two T i run gfo and carbon in a dual reactor , euro reef skimmer / have a koralia 4 and a koralia 2 for flow
my problem is that all my zoas aren't growing at all in fact they are declining
i have lost a couple of frags of bird nest and some others
my parameters are calcium 375-alk 8dhk- salinity 1.026 -ph 8.0 -phosphates 0.0-ammonia .05 ? -nitrates 0 -nitrites 0 - temp 78 / i use ro/di all the time
anybody have any suggestions ?
no pests that i know
thanks
Manny

 

[Enterprise]

The first thing I notice is that your Calcium is too low. Most people recommend 420-450 ppm for good coral growth. What is your Magnessium like?

 

[Behrmon]

What kind of bulbs are these 100 wt?

Yes Mg?

Maybe bring alk up 1 "pt"

Maybe up the Korallia 2 to a 4?

Try running a few weeks w/ no gfo?

 

[mstrassbur]

What kind of bulbs are these 100 wt?

Yes Mg?

Maybe bring alk up 1 "pt"

Maybe up the Korallia 2 to a 4?

Try running a few weeks w/ no gfo?

I change the bulbs to
2 150 watt phoenix made in japan hexarcblue 14000k
20621 mh 150w/de
2= t5 v-ho
Date 11/13/2009.
mg is 1350
I'm thinking of changing the 4 and 2 for two 3's as the 4 is causing sand storms and scouring the bottom
I'm running the gfo only about a month to battle a hair algae outbrake which is almost all gone now.manny