corals starting to get lighter/white......

[Skeptic9962]

ive noticed lately that a few of my corals have really started to show signs of stress...when it all started was when i did the RB treatment after that everything started to get a bit whiter...i did use a different carbon cause i ran out of my nice stuff...i switched from using ROX 0.8 at about a cup every week and then ran out and picked up kent carbon and used around 2 cups of that right after i dosed for RB ive been told its possible that i used too much carbon too fast...and made the corals get burnt a bit...is this possible....

current params.

SG 1.026
alk 8dkh
calc 400
mag 1275
ph 8.2-8.4
phos 0
nitrate 15 (still working on this)
nitrite 0
amon. 0
temp. 79-80

lighting is a Outer orbit 150w with (4) 24w t5s this is over a 23" deep tank 33gallon....whats wierd is it seems to be mainly my montis... superman is a bit lighter but rainbow and my poker star are both really light they still polyp with the colors of the polyps but the body is a white/very light blue.....also my phils granulosa is starting to get a bit lighter in color..

i do 10 gallon changes with IO once a week, and change my carbon once a week i bought a bag of BRs carbon today to try it out and replaced the mesh bag with a phosban reactor for the carbon used 1.5 cups this time....

just stressed out is my guess from too much light penetration all at once after using so much carbon? whats wierd though is the phils came from BR in there frag tank and that has way more light....

 

[Jan]

It is definitely possible to use too much carbon; I've done it myself and experienced TN on a few corals as a result. What is your water volume?

 

[Skeptic9962]

the total volume sump and tank is right around 50gal. my main display is 33gal.

 

[kevinpo]

In your case my guess is that the color change is due to a reaction from the chemical not carbon. Wth the size water changes you are performing I wouldn't think your water would get too yellow.

Regards,
Kevin

 

[Jan]

...and in my opinion (in addition to what Kevin said above), you are using too much carbon for your tank volume. I only use 1+1/4 c. carbon in my 140g net system, changed every 3 weeks.

 

[Skeptic9962]

yeah ill try droping it from 1.5 cups a week to 1cup every 2 weeks and see how that does...

 

[Skeptic9962]

would shortening the MH light period for awhile possibly help? or would that just agitate them more...my current schedule is:

T5s 10-9
mh 12-7

 

[kevinpo]

would shortening the MH light period for awhile possibly help?

I don't think that's necessary.

Kevin