Darkening zoa, good or bad?

[Cbray305]

Hey all, thanks in advance. I bought this zoa for 20$, was light in color, pink/bluish i would say, more so with the blues. Ive had for roughly 2 months, kept on sand because i am dealing with a green hair algea problem, I am scrubbing rocks every so often. Lighting is a fluval sea marine, 59 watts, 25 000k, enough for softies. Parameters are all at 0, though i have this algea problem that started with the new lights. Anyways when i first added the zoa, it was light in color, now alot of the polyps are darkening to a darker blue? Losing a bit of the pink/red tentacles. So is this because of lighting/flow? Maybe it was almost bleached when i first purchased and now it true colors are coming out? Or any opinions on what maybe going on? Pictures are of first purchase and where it is at now. Thanks again!

 

[jeffchapok]

I would say low nutrients are your problem. Zoas from my LFS always get more colorful after I've had them a couple of weeks. My NO3 and PO4 always run 40 and .5 respectively.