SPS growth but turning brown!

[mojojojo]

i have a couple of SPS' that have faded to brown but have tremendous growth on them,

all my params are within the normal water condtion.
2x250w 20k bulb over a 4ft tank.
2xmp40w

im puzzled with their condition

 

[dmorazan]

lighting

 

[boodlefish]

lighting

i disagree. i say too high of nutrients!

 

[borcu]

so if growing tips blue but the body turns brown can we say because of zooxanthellae increase?

 

[mojojojo]

yup brown body and blue/white tips of growth... basically the colors of my sps' are either brown.. or from brown they turn into a dark shade of green.

 

[palyam]

and I'd say lighting also. 20K has a low PAR, and without a really good reflectors the light might be not enough for colors. I'll change one of the bulbs to 10K, and you'll see results soon.

Needless to say, nitrate and phosphate should be zero

 

[recife111]

2x250w 20k bulb over a 4ft tank.

How long have you had the 20k bulb?
bulbs that are really blue loose a lot of intensity after 6 months.
Also being 250w it will be worse.

I had two on the same acropora under different light in my tank.
The one under 14k Blv had tremendous growth and colour, the one under 20k radium hardly grew and colour was not as good, started to lose colour badly after bulb was 6 months,

 

[boodlefish]

a pic would help