sps corals dying in upper region of the tank

[[email protected]]

Hi everybody,

a friend of mine has a very strange problem. His sps corals are dying,
but only in the upper region of the tank. The tank is 2x1x0.8 meter, it
is lit by two 400 Watt metal halides and two 250 Watt MH's. The tank is
fitted with a large kalkreactor and skimmer, all the parameters are
fine. On the bottom and lower part of the tank everything is doing
well, but in the upper region all sps eventually die, even soft corals
aren't doing well in that area. A small sps fragment may do very well
in the lower part of the tank, but as soon as it is placed in the upper
region it starts dying. One would suspect light to be the problem, but
even on the back wall, where the light intensity is condiderably lower
than on the bottom, the problem occurs.
Any ideas ?

Walter

http://www.uia.ac.be/u/dorrine/HOMEPAGE.HTML

[Marx]

Could be UV problem? Maybe he uses double-ended without UV-shielding
Marx

[Walter Dorriné]

Somebody on this newsgroup suggested checking the temperature at
different levels, I will ask my friend to do so and get back here with
the results.

Walter

[Walter Dorriné]

The 400's are shielded the 250's aren't. I had a normal glass tube cut
in two (length-wise) for him in our glass workshop, I suppose ordinary
glass stops UV?

Walter

Marx wrote:

> Could be UV problem? Maybe he uses double-ended without UV-shielding
> Marx
>

[skozzy]

This has just happened to me, the skin on the SPS started to peel off, I
moved it to another tank and salvaged some frags of it, the skin is 99.9%
gone now on ALL but one frag. The same SPS when I put it in the tank about 2
months ago had a peice break off, this peice is at the bottom of the tank
and is still doing very well. In my tank the obvious difference is the good
frag is at the bottom of the tank, there is low water movment around it, the
SPS that deskined was at the very top near or water return from the sump.

I read that these SPS corals don't like a lot of temp change, and I have
been thinking that this might be the cause, as I have the heater in the sump
and maybe the water temp is rising too far from the water return before the
chiller in the water outlet side of the tank kicks in, so this SPS would be
at the front line of the temp changes. Also being close to the top it might
be getting effected from the top level water temp from the lights and at
night when the lights are off the cold air cooling the water also.

Water conditions in the tank I assume are the same everywhere, so the temp
is something that i can't see but can only guess, the frag at the bottom of
the tank that is still doing very well is very close to the substraite, so
that makes me think the temp down there might be more stable.

> wrote in message ...
> Hi everybody,
>
> a friend of mine has a very strange problem. His sps corals are dying,
> but only in the upper region of the tank. The tank is 2x1x0.8 meter, it
> is lit by two 400 Watt metal halides and two 250 Watt MH's. The tank is
> fitted with a large kalkreactor and skimmer, all the parameters are
> fine. On the bottom and lower part of the tank everything is doing
> well, but in the upper region all sps eventually die, even soft corals
> aren't doing well in that area. A small sps fragment may do very well
> in the lower part of the tank, but as soon as it is placed in the upper
> region it starts dying. One would suspect light to be the problem, but
> even on the back wall, where the light intensity is condiderably lower
> than on the bottom, the problem occurs.
> Any ideas ?
>
> Walter
>
> http://www.uia.ac.be/u/dorrine/HOMEPAGE.HTML
>

[Simon O'Keeffe]

Could be elevated phosphate levels.
Apparently the test kits don't measure all forms of phosphate very well
and this can lead us to believe that we have very little phosphate when
in fact there is some there.
the main problem with this phosphate is that is fuels photo synthesis
too well and the corals can produce too much oxygen from the lighting
that they receive. This can cause them to bleach or RTN or to change color.
I'd make sure you have you water tested with a decent phosphate kit.
Simon

skozzy wrote:

>This has just happened to me, the skin on the SPS started to peel off, I
>moved it to another tank and salvaged some frags of it, the skin is 99.9%
>gone now on ALL but one frag. The same SPS when I put it in the tank about 2
>months ago had a peice break off, this peice is at the bottom of the tank
>and is still doing very well. In my tank the obvious difference is the good
>frag is at the bottom of the tank, there is low water movment around it, the
>SPS that deskined was at the very top near or water return from the sump.
>
>I read that these SPS corals don't like a lot of temp change, and I have
>been thinking that this might be the cause, as I have the heater in the sump
>and maybe the water temp is rising too far from the water return before the
>chiller in the water outlet side of the tank kicks in, so this SPS would be
>at the front line of the temp changes. Also being close to the top it might
>be getting effected from the top level water temp from the lights and at
>night when the lights are off the cold air cooling the water also.
>
>Water conditions in the tank I assume are the same everywhere, so the temp
>is something that i can't see but can only guess, the frag at the bottom of
>the tank that is still doing very well is very close to the substraite, so
>that makes me think the temp down there might be more stable.
>
> wrote in message ...
>
>
>>Hi everybody,
>>
>>a friend of mine has a very strange problem. His sps corals are dying,
>>but only in the upper region of the tank. The tank is 2x1x0.8 meter, it
>>is lit by two 400 Watt metal halides and two 250 Watt MH's. The tank is
>>fitted with a large kalkreactor and skimmer, all the parameters are
>>fine. On the bottom and lower part of the tank everything is doing
>>well, but in the upper region all sps eventually die, even soft corals
>>aren't doing well in that area. A small sps fragment may do very well
>>in the lower part of the tank, but as soon as it is placed in the upper
>>region it starts dying. One would suspect light to be the problem, but
>>even on the back wall, where the light intensity is condiderably lower
>>than on the bottom, the problem occurs.
>>Any ideas ?
>>
>>Walter
>>
>>http://www.uia.ac.be/u/dorrine/HOMEPAGE.HTML
>>
>>
>>
>
>
>
>

[PaulB]

No, it depends on the glass. UV shields are a special sort of glass. I
think that UV is the problem.

http://www.advancedaquarist.com/issues/nov2002/feature2.htm

http://www.coralforum.com/ftopic888.html&highlight=





"Walter Dorriné" > wrote in message
...
> The 400's are shielded the 250's aren't. I had a normal glass tube cut
> in two (length-wise) for him in our glass workshop, I suppose ordinary
> glass stops UV?
>
> Walter
>
> Marx wrote:
>
> > Could be UV problem? Maybe he uses double-ended without UV-shielding
> > Marx
> >
>
>

[Dinky]

"Walter Dorriné" > wrote in message
...
| Somebody on this newsgroup suggested checking the temperature at
| different levels, I will ask my friend to do so and get back here
with
| the results.
|
| Walter
|

Walter, could you please quote the posts you are replying to? It
complicates things a bit.

thank you muchly

Bill

[skozzy]

> I'd make sure you have you water tested with a decent phosphate kit.

That's interesting, because I done a major water change to remove excess
phosphate, and now I find out that my Hagen PO4 Test Kit might be faulty, I
put two kits side by side and read the instruction books from both, one book
says add 3 drops of part 1, then 3 drops of part 2, then 1 drop of part 3.
The other book says 3 then 3 then 3 drops of part 3. Both tests produce
major different results. So far emails with Hagen have not been processed so
I have no answer on this. But phosphates might be bad now where as before
they wern't or vice versa, it's hard to tell.

The strange thing is tho, a peice of the same coral on the bottom of the
tank is doing very well, the main peice is pure white now. That is why water
temp is my main thought of the problem.

[Walter Dorriné]

Sorry Bill, that reply came by mail.

Walter

Dinky wrote:

>"Walter Dorriné" > wrote in message
...
>| Somebody on this newsgroup suggested checking the temperature at
>| different levels, I will ask my friend to do so and get back here
>with
>| the results.
>|
>| Walter
>|
>
>Walter, could you please quote the posts you are replying to? It
>complicates things a bit.
>
>thank you muchly
>
>Bill
>
>
>
>

[Rod]

>That is why water
>temp is my main thought of the problem.

for the temp to be that big of a difference, theb water flow must be very very
very low, or no flow at all. .. doesnt add up.

[Walter Dorriné]

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I agree with you, Rod, there are 2 Tunze stream pumps in his tank,
12000 liter per hour each.&nbsp; Temperature must be homogeneous over the
whole tank.<br>
<br>
Walter<br>
<br>
Rod wrote:<br>
<blockquote type="cite"
">
<blockquote type="cite">
<pre wrap="">That is why water
temp is my main thought of the problem.
</pre>
</blockquote>
<pre wrap=""><!---->
for the temp to be that big of a difference, theb water flow must be very very
very low, or no flow at all. .. doesnt add up.
</pre>
</blockquote>
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[Wayne Sallee]

Ok, so what is the water temp running?

Wayne Sallee
http://members.aol.com/waynesallee/weblink.htm