what causes coral bleaching?

[shoelevy]

recently, my don't know wat coral...should be leather finger coral suddenly started bleaching

i tested chem

nh3 0

no2 0

no3 20

ph 8.3

temp 26

Ca 450

neve test mg cos no test kit

my mushies doing very well....i did does trace elements but never above the recommended dosage...infact i dose 3/4

its been with me for 1.5 mths

anione has any ideas y it suddenly bleached?

[blueheaven]

Corals bleach when they expel zooxathellae mainly due to poor water quality, not enough lighting and high water temperatures

[pisces]

Agree with blue.

Thought temperature rise is cited as the most common cause of bleaching, it doesn't seem to be the problem in your case.

Not very sure abt this, but I think low salinity, water current and proximity to agressive corals could also be the stress factors.

[shoelevy]

hm...my corals haf been with me for 6weeks now.

i heard corals haf a slow metabolism rate...could it be that sth was already wrong 6weeks ago but due to its slow metabolism so now then it start bleaching???

i do suspect its my lights but i'm not sure so i asked...i'm using 2 t8 tubes 70W for 4 footer...is this low enough to cause bleaching?

[blueheaven]

well it actually depends on your tank's depth

light intensity drastically decreases as it goes deeper

[giantbicycle]

do u aclimatise it propely? or is it jus due to shock of the intensity of lights..this will make it bleach too

[blueheaven]

yes, bad acclimatization will result in bleaching too because the coral is unable to change its zooxathellae to suit the current lighting.

In other words, the coral itself is starving to death

[shoelevy]

question:does high phosphate level cause bleaching?

[lightningstrike]

question:does high phosphate level cause bleaching?

not only bleaching but oso certain death. PO4 inhibits calcification in stoney corals (sps & lps).

[shoelevy]

mine's a softie....aiya...sian...can't find out the prob with it.

i was suspecting low lights but its bleached so much i don't think it'll last long enough to wait to be transfered to my 5footer with mh lights....will some kind soul take it in and keep it until i can bring it back?

u wanna frag it also can....as long as u help...think i'll post a new thread on this

[shoelevy]

ok

i made some calls to lfs asking them wat's wrong tt caused the bleaching and here's wat they said

hope other newbies will learn from this

they told me there are 4 primary reasons for y bleaching occurs

1)low iodine levels

2)no feeding of coral foods

3)high water temp

4)low lights

when i described my symptoms of button polyp slight bleaching, finger leather full scale bleaching and mushies no problem...they all said confidently that it was low lights.

cause mushies is the only one out of the 3 tt can tahan low lights.

if 1 2 or 3 were the reason behind the bleaching...then ALL of the corals would bleach...but since mushies were not affected...so it must haf been low lights

anwiae...thank buddha i found someone to take them in...