Growing out corals.

[whatcaneyedo]

Detectable phosphate is too much phosphate and will certainly effect the colour and health of your coral.

Here is a little light reading:
Phosphate and the Reef Aquarium by Randy Holmes Farley
http://reefkeeping.com/issues/2006-09/rhf/index.php

[Bugger]

Are you changing your Ro filters. How old is the membrane how old and what type of carbon blocks are you using. What kind of water does your city use. you might have added chlorine to the system.
What are you checking your salinity with
something clearly happened

[WarDog]

So many variables.

What kind of frags?

[Frogger]

Could be a million reasons. Need way more information. Like how long has the tank been setup. how long you have had the corals, what are the corals, , what is the temperature, what are the nitrates (0 nitrates can cause loss of colour), what else is in the tank ( corals) what are their colours like etc.

Often it is just the stress of cutting a frag and moving to a completely new tank will cause a coral to go brown. The good news is fix the problem and the colour will come back. If the problem is just stress sometimes it takes 6 months to a year for a coral to recover. Higher end corals are more temperamental which is why they are higher priced.

[DorySaid]

You mentioned phosphate but not nitrates. Its sounds to me an excess nutrient thing possibly? But like they said it could be many things. You mentioned ramping leds but where did you get the corals and how was their water and light in comparison to yours?

[Ram3500]

I would guess that it's the LEDs.Or it's your phosphate or it's your frags miss the ocean. My vote is they miss the Ocean.