Coral color shifting

[cook]

Currently I am running 2x175 14 k hamilton and 3x110 vho, 2x110 10000k. Everything that I bring from my prop tank(6'' high with3x110 vho 10000k and 3x110 actinic) into my tank at home changes color. If it is green it turns blue at the top and the all the way down to eventually turn clear . Tricolors turn clear. My red cap does not change. I have a tort that has been in there for two days and the tips are changeing to a light blue. Maybe too much blue light, any ideas.

alk 3.0
cal-500
ammonia-0
trite-0
phos ?
temp78-80
sal-1.022

[MCsaxmaster]

Could be bleaching due to too much light, could also be that a specific gravity of 1.022 is doing a number on them. This should be at least 1.025, if not 1.026. Actually, I just read a study examining bleaching due to low salinity. The corals were quickly affected (killed sometimes) by very low salinities, but were also very affected by salinities a bit below the norm. They showed greatly reduced photosynthesis/bleaching at specific gravities of about 1.020-1.023. Something to think about.

Best,

-Chris

[cook]

The change always seems to start at the top, if this is a stress response than wouldnt the coral bleach all over. If this is the case why is my monti digi and cap fine. I am slowly pulling up my sal but I think it lies in the lighting.

[cook]

Also my corls grow like weeds, They are going to a clear not bone white color. Do bleaching corals turn clear?

[MCsaxmaster]

The change always seems to start at the top, if this is a stress response than wouldnt the coral bleach all over.

Because light (oxidative stress) can either cause or compound bleaching. As I said it might be just the light, but the low salinity isn't doing you any favors either.

If this is the case why is my monti digi and cap fine.

Because they are different species with different tolerances...

I am slowly pulling up my sal but I think it lies in the lighting.

Ok. That very well could be, but as I said, the abnormally low salinity isn't helping either.

Also my corls grow like weeds

Ok, good.

They are going to a clear not bone white color. Do bleaching corals turn clear?

Sure. The coral tissue doesn't actually turn white, though it can become clear and show the white skeleton underneath. When bleaching is moderate, the coral remains its normal color, though a lighter shade. As the bleaching becomes more severe, the coral tissue becomes more transparent and the skeleton underneath becomes more visible, hence a "white" coral.

Best,

-Chris

[DaddyJax]

This is a site that our reef club forum found. Hope it helps. It explains about the differeent species and there natural "sunscreen" and UV damage. http://www.advancedaquarist.com/issues/aug2004/feature.htm

[cook]

So do you guys think I should cut back to 2 or 3 vho instead of 5.

[MiddletonMark]

What period of time are we talking about?

Is this happening soon after moving the corals to the tank, or over time?

I've found some Acroporids change coloration over time depending on my overall water quality, light penetration [organics] as well as where they are positioned in the tank regarding light. But, if we're talking coral loss - and you acclimate corals to higher lighting slowly - IMO it's the water more than the light.

I see Nitrite listed - have you tested it?

I too would agree with Chris about the salinity. I don't see a reason not to run it at NSW [1.025-6] levels.

I'd drop calcium, bring up Alkalinity a bit to balance with it - I'd consider regular water changes on a steady basis for a while - in my experience they seem to remediate most imbalances.

--
On the overall light ... how long are you running them?

[cook]

This is a change over time maybe 2 months. Trites are 0. I have always done a 20 gal change every 2 to three weeks. Lights are on vho for 12 hours and metal halide for 7. I( have also noticed one of the acros that was originally green is now turning purple at the tip. Green to blue to clear to purple?

[cook]

They all display polyp extension and are growing well.

[MiddletonMark]

Crazier things have happened, I guess.

Sorry - I took `trites' to mean Nitrites ... sounds good.

What kind of filtration is in the tank? Water flow comparable?
Cleaned out the sump recently? When my color fades a little I often find a whole ton of crud in the sump.

Have any pics?

Not sure if I can help, but sometimes just laying out things makes ideas for improvements more apparent.

[cook]

I run a sealife skimmer with a rio-gph 1200, lots of live rock, carbon and cheto alge. My flow is good, I have a mag 9.5 on a scwd and a powerhead on each side fo the tank. This tank is 1.5 years old.

[cook]

Ok I changed the lighting, I put in more 10000k vho. Now my blue acro is browning out. This was one of the most colorful formosa I have ever seen. Will the color come back in the right conditions. Sal is 1.027 and phosphates are zero. I was thinking of starting up the cal reactor this weekend. Is this a good idea?

[cook]

I have a recent pic of both in my gallery if you would like to take a look.