hard coral dying from base up?

[Dave Bardin]

Maybe this should be in the newbie section but my tank has been great for 9 months, now this. The hard corals I have; birds nest, montipora, some green tree lookin thing (ok so I don't even know what I have) just now started turning white from the base moving up. I tested the water and everything was perfect except ca at 520. I started feeding way less recently (last 2-3 weeks) because whenever I went out of town for a few days, everything looked so happy when I came home. Also, I changed my top off system and almost over night 4 days ago I dropped the salinity from 1.025 to 1.023. I'm decreasing ca dosing, feeding a bit more now and (slowly) bringing up salinity.

See the pics, any ideas?

 

[Dave Bardin]

You can see the bleaching in the very center of the base on the birds nest and my "green tree". One of the lower branches has bleached completely. Also, it looks like the montipora is actually less bleached when one upper portion slightly covers a lower portion. The green looks a little less bleached under the overhang. There are also a couple little spots of alge starting on the montipora, (dead spots?)

Please help me reverse this, quick!

 

[cloak]

STN maybe? Try looking through the sps forum. There are a lot of threads where people are experiencing the same problem your having.

 

[Dave Bardin]

OOPS! Forgot to mention, I changed my 2 T12s (I have a Solaris LED and 2 T12s) to actinics from the 50/50 10k/daylight somethinerothers a month ago. Then I changed the rear T12 back to the 50/50 and left the front T12 actinic (I did this almost a week ago). I guess I have changed a couple things after all.

I hate when I do that!

 

[Dave Bardin]

STN? Not familiar with that, Stupid Tinkering Nerd?

I'll check the other posts again.


Thanks

 

[Allmost]

Hello Dave

what are the exact values ? KH, CA++, MG++, NO3, Temp, po4 ?

what is the lighting, how big is the tank and how much of flow ?

all these are needed to be able to evaluate what is happening and to pin point the problem

the pic of birdsnest, looks like flow Issues, less flow through the base and within the colony.

salinity drop from 1.025 to 1.023 in one night ? that's alot of stress for SPS so that maybe the Issue . SPS love stability.

 

[zachfishman]

I can't speak for the Montipora, but Birds Nest corals are notorious for going STN at the base and inner areas when they grow larger - the block their own flow. Make sure your powerheads are good and clean to ensure they're performing efficiently.

Do you run GFO? Have you changed it out recently?

 

[Allmost]

STN? Not familiar with that, Stupid Tinkering Nerd?

I'll check the other posts again.


Thanks

Slow Tissue necrosis

if not stopped it will turn into RTN : rapid tissue necrosis

 

[zachfishman]

haha, I'm mixing them up. either way, BN are susceptible.

 

[Dave Bardin]

Thanks for the clarification on STN.

Now that you mention the GFO, here's yet another thing I messed with: a week ago I replaced the GFO media with straight carbon in my reactor (the fishy 550 I think). I also did a 35 gallon water change on my 180 (plus the larger magnaflow sump).

I don't think it's the flow because it happened to several corals at the same time, some of which are still getting the same really good flow.

One other coral not pictured did do the RTN thing I think already.

The tank is a bow front 180 with the magnaflow sump, a euro reef 180(?) skimmer, a solaris LED with 2 T12s (one aquasun and one actinic), 2 Hydor Koralia Magnum 6 (1 at each end) and a rio 900 across the back.

The parameters are PH 8.2, Ammonia 0, Phosphate 0, Nitrite 0, Nitrate 0, Ca 520, 125.3 ppm KH, salinity 1.023, temp 76.1. Tank is 9 months in and I haven't added anything or put my hands in for over a month.

Summary of changes;

changed 2 T12 VHO 10k out for 2 actinics 1 month ago.
changed 1 of the actinics back to aquasun 10k 1 week ago.
started feeding way less (practically starving my tank?) 2 weeks ago.
swapped out the phosban for carbon 1 week ago.
35 gallon water change 1 week ago.
dropped salinity (overnight) from 1.025 to 1.023 4 days ago.
I think that's it.

With the details, what do you think I should mess with first?
I'm slowly bringing up the salinity, increasing the light time by 3 hours (too crazy?), feeding way more. Is this all just gonna make it freak out worse?

 

[plyle02]

IMO, too many changes in such a short period of time. Changing GFO always causes my corals to get upset during change, as well as GAC changes. Changing lots of water, unless at tank spec in all params, could also cause a swing. Not to mention temp... You mentioned you also changed lighting? All these I would space out... SPS will react to all the mentioned above, but if all at once, could send your corals in a RTN spiral... Damage done, now just stop dosing really anything until you lock your params back in. Once you do, then just observe... Most SPS don't like rapid changing environments...Find a good nutrient import system, a rapid export system(great skimmer), lock params in, even with a w/c change, not too much change from tank's current levels...If you run GFO, introduce slowly during changes, either cut back the flow, or go lighter and add more later, this applies to GAC IMO too... HTH's... Best of Luck!!!
Regards,