Coral bleaching due to water change

[bcheriyan]

Hello all
Not Sure why this happened my Pink Bird Nest Coral tree has bleached over night .. What could have triggered this ?

Ca 480
Alk 8
No3 0
P04 0
Ph : 8.1 to 8.4
Sal : 35 ppt

1) Did a water change but looks like the water used was higher temperature than the tank.
2) Also the salinity was around 33 ppt with the water change I brought it back to 35.
3) Also 2 weeks ago I reduced the the light cycle to get more blue light in the tank and the peak light hours is reduced to 6 hours instead of 8 hours(). Over all the tank is lit for 12 hours.

What else could have bleached my pinkie ..
THx

 

[Mhayes462]

Hard to tell by the pics, but looks like its not bleached but dead on that part. Does it still have polyps there?


Mike Hayes

 

[bcheriyan]

I do not see polyps on that part .. Also I have Bristol Worms you can see in one of the pictures it is cleaning the dead part .. THis happened over night and all other sps are doing alright ..

 

[aqua80]

stung by your torch coral ?

 

[Laddy]

I would probably start cutting off the dead areas well into healthy tissue--I'm thinking STN without knowing the whole story.

 

[bcheriyan]

It is possible that my torch stung my pinkie tree .. I will start removing the dead areas ..

 

[karsseboom]

Pinkie tree?

 

[spsexpert]

how big of a water change did you do?
large amounts of water change can remove too much nutrients from the water column, sps need some no3 and po4 to survive
do you run carbon or GFO as well? they can also be contributing factors
try to feed your tank more or dose amino acids to balance nutrients, should buy a hanna checker to test po4 properly

 

[bcheriyan]

I did a 25 gallon water change on my 140 Gallon System .. The thing that might have gone wrong is that DT tank had Sp :33 ppm and the water I used had a 38 ppm to adjust the over all ppm to 35 .. That could be one Issue . Also I saw a the Bristol Worms eating the live side at night so currently the Whole Pink Bird Nest Coral is looks bleached .. . But I have other Pink Bird Nest Coral which is doing fine ..

 

[Digitalelectric]

I routinely do water changes that large on my 150 gal system. No problems. I also toy with salinity to keep it in a target region. How long after the water change did it do this?

 

[bcheriyan]

Usually I do 15 gallon change but this time I did 25 gallon also I have pumped 25 Gallon at a time from the sump and then Pumped in the new 25 g and all in about half hour ... May be shock ..