Mobile Bay Reef Keepers

Hey all. I've noticed something going on with my corals that I just can't figure out. I have bought frags as well as mature pieces and after a week or two in my tank the color starts to fade. Mind you it's not bleaching, because 1) they still have color--just not intense and 2) my corals are growing very well. An example is I bought a frag of GARF Purple Bonsai two weeks ago and it has grown almost 1/8" since then.

Here is my tank info:
3 T5 ATI bulbs, Hagen Marine Glo--four months old. Generating 500 PAR at the surface and 200 on the bottom sides. Run blues for 10hrs/day and the whites about 7.5/day.

pH-8.1, Ca+-420, Alk-4.2meq/L, Mg+-1365, temp-83, SG-1.027

All of the bad stuff (NO3 etc) are undetectable.

I am really trying to figure out what is going on with this. I could understand if my corals where suffering and not growing, but mine aren't. It was suggested that it could be low iodine or other trace mineral/elements.

Really would appreciate any help or suggestions.

Thanks
Andrade

Try doing steady water changes for a few weeks, that should tell you something.

If you haven't had the tank very long it's possible the water is too clean, with saltwater systems you want to only do a 10% water change or else you might shock the system. It's also possible that they are receiving too much or too little light, you can contact the person who sold you them and see what parameters they used for their lights.

Also colors are subjective. Are you sure they are fading?