need help with corals

I was wondering if anyone can help me with my little problem. I have a gold finger leather and a blue xenia in my tank, but they do not want to bloom fully. I don't know why this is happening, I've had them for about a month now and when i first got them they bloomed good, now they just come out a little. I'm concerned that it may be my lighting, I 4x54W lamps on a 90 gallon aquarium (48 inch),I do my water changes every two weeks, Nitrates are at 15, Phosphates 0.5, PH between 7.8-8.0, temp 77.8-78.4, and both corals are about are at the top of my rock, I have tried to move them to different areas and they are in med-firm flow, can someone help me, THANKS

 

When is the last time you changed bulbs? pH should be between 8.1 and 8.3. What is your alkalinity and calcium?

 

Also whats your SG? It should be 1.023-1.025 for Reef tanks.

 

bulbs are about three months old, calcium is at 450,

 

SG is 1.023-1.025

 

Alright your calcium is good and your SG, You may need to bring your pH up to atleast 8.3. Your nitrates are alil high try W/C, They also need medium flow.

 

ok thnx Xiz, but what about the lighting is it OK, is is 216 w enough

 

Are those regular lights or compacts or T5's?

 

sorry T-5, 2 white 2 blue

 

Is it t5 or PC lighting? And how old is the tank?