SPS and Hard corals browning out!

[hometown9]

Softies and everything else seem to be OK, but hard corals (SPS, monti) just brown out within 2 weeks of putting them in. My nitrates were high (60) for awhile but I've brought them under control (10). Lights are mostly blue at this point, no white, red or green (AI HD26). Any ideas? It's been about 3 months of this. So frustrated.

CA: 460
Mg: 1500
Alk: 9
NO3: 10
Ammonia: 0
Nitrite: 0
Ph: 8
Sal: 1.026

[Tired]

Why no white light? 

[WV Reefer]

1 hour ago, hometown9 said:

Softies and everything else seem to be OK, but hard corals (SPS, monti) just brown out within 2 weeks of putting them in. My nitrates were high (60) for awhile but I've brought them under control (10). Lights are mostly blue at this point, no white, red or green (AI HD26). Any ideas? It's been about 3 months of this. So frustrated.

CA: 460
Mg: 1500
Alk: 9
NO3: 10
Ammonia: 0
Nitrite: 0
Ph: 8
Sal: 1.026

 

How old is the tank?

[mcarroll]

1 hour ago, hometown9 said:

Softies and everything else seem to be OK, but hard corals (SPS, monti) just brown out within 2 weeks of putting them in. My nitrates were high (60) for awhile[...]

High nitrates cause the coral's dino's to divide a lot which gives the coral a brownish hue. 

 

It can lead to bleaching too.  Keep a close eye on nitrates AND phosphates.  As long as phosphates doesn't get <0.03 ppm things might be fine.   (But with nitrates that high, it can throw things off...so don't assume....test.)

 

1 hour ago, hometown9 said:

I've brought them under control (10)

So why were they so high and what did you do to get them down to 10?  Be as detailed as necessary.  🙂

 

1 hour ago, hometown9 said:

Any ideas? It's been about 3 months of this. So frustrated.

If you're saying the tank's three months old, then that's the main problem....rushing things a bit.  😉 

 

The corals in the tank are looking bleached in the photos, so keep your fish well fed, consider some small feedings just for the corals until their color returns.

 

Might have more suggestions based on the answers you give above.

 

1 hour ago, hometown9 said:

CA: 460
Mg: 1500
Alk: 9
NO3: 10
Ammonia: 0
Nitrite: 0
Ph: 8
Sal: 1.026

Seems Ok....just need a measurement for phosphates ASAP.

 

1 hour ago, hometown9 said:

Lights are mostly blue at this point, no white, red or green (AI HD26).

I would not mess with the lights....if you had a standard setting you were running, I'd go back to it.  If you didn't, then set the colors to something like 20,000K....whatever looks good to you.  If you can, use a lux meter or PAR meter to set the intensity.  (lux app is free.  lux handheld is around $10.  PAR rentals aren't a lot more.  No good reason not to use a meter of some kind vs guessing.)

[seabass]

SPS will brown when the light intensity is too low.  This is caused by golden brown color of the symbiotic algae (zooxanthellae) within the coral.  When lighting is too low for that particular coral, the zooxanthellae can increase in number, making the coral turn brownish in color.

 

However, if the light is too intense, excess oxygen created by photosynthesis can create a toxic condition and the coral may eject the algae (resulting in coral bleaching).  Make intensity adjustments slowly (over several weeks).  If you start to notice any bleaching, you may have to decrease the intensity.

[mcarroll]

That's right – too little light is another circumstance (along with elevated nitrate levels) that can cause browning!

 

Apparently they have found photosynthetic corals living at great depths that were almost black with dinos.  That's adaptation!!

[seabass]

49 minutes ago, mcarroll said:

(along with elevated nitrate levels) that can cause browning

I haven't read about nitrate specifically causing browning.  However, this study addresses increased phosphate levels.  Again, it was suggested that it was the increase in zooxanthellae which caused the change in coloration.  I suppose we should think about it as an increase in nutrients (assuming no limiting factors), versus one particular nutrient, which can cause browning.

[mcarroll]

Neat study -- and from 2011!  (Wish ReefBuilders had given the article title or some way to look it up....they just gave a link to the Journal it was in.)

 

They proved in the study how silly the concept (as commonly seen, anyway) of low nutrient reefing really is*!

 

In the process of growing Acro's in the presence of almost 1.0 ppm of phosphate (or more!) they also noticed that while the corals were fast-growing and healthy, they did not demonstrate the stereotypical "white growth tips" usually seen by fast growing corals, like this photo I snatched from google:

  

 

Instead the high-P acroporas had dark tips.

 

Keeping the tips de-populated of dino's under more ordinary P-circumstances and self-shading are just two aspects of an overall strategy corals must use to keep their dino's in check.

 

Their symbiosis with dino's is usually presented as a beacon of balance and harmony...which I mostly agree with....but what it takes to achieve and maintain that balance and harmony isn't so well-known. 

 

When you really look at it, the balance and harmony is all on the surface...at their core, these corals are virtually performing a magic trick to make it all work and to keep from being destroyed in the process.

 

I like the provocative sentiment in the title of this article on the topic:

Is the coral-algae symbiosis really ‘mutually beneficial’ for the partners?

 

This is the quote I saved from it three years ago (looks like the PDF is still online to read the whole thing.....which I recommend!!):

Quote

In terms of the demand for CO2(aq), an enlarged endosymbiont population increases the likelihood of CO2(aq) becoming a limiting internal substrate during periods of peak photosynthesis [18, 19]. Several environmental factors favour increased zooxanthellae densities (particularly on a per host cell basis), including: (i) elevated nutrient levels (e.g. dissolved inorganic nitrogen, DIN) in the surrounding sea water [20], elevation of the CO2 partial pressure (pCO2) in the surrounding sea water [21], and diffusive (i.e. branching) coral colony morphologies [22]. Experimental manipulations confirm the higher expulsion rate of zooxanthellae during periods of high irradiance in branching corals [23] and in corals exposed to DIN and pCO2 enrichment [24, 25].

 

*That's a lotta phosphate!!  We wondered out loud in the Dino thread on the other board whether there was any kind of upper "safe limit" for phosphates....folks in our thread were sometimes dosing up to 0.20 ppm and it was clear that there was no harm to corals...if anything the opposite, kinda like "overdosing" calcium when that happens....and that was almost literally nothing compared to the levels this study tested.

[mcarroll]

These two go into it as well:

https://reefsuccess.com/2016/10/11/nutrient-balance/

https://reefsuccess.com/2018/08/27/phosphate-deficiency-promotes-coral-bleaching-and-is-reflected-by-the-ultrastructure-of-symbiotic-dinoflagellates/

 

This one kinda hits the nail on the head:

https://reefsuccess.com/2017/04/18/impacts-of-nutrient-enrichment-on-coral-reefs-new-perspectives-and-implications-for-coastal-management-and-reef-survival/

 

Here's the link for the Dunn article mentioned in reefbuilders:

https://doi.org/10.1016/j.jembe.2011.10.013

Title was "Effects of phosphate on growth and skeletal density in the scleractinian coral Acropora muricata: A controlled experimental approach" and it looks like it was actually published in 2012. 

 

Only the abstract appears to be available.

 

What would be interesting, at least from an aquarist's perspective, is what would have happened if they had scaled calcium and magnesium (and maybe alkalinity too) up with phosphate levels.  Wonder if that would counteract the brittleness?

[A.m.P]

Hobbyists really don't help much when it comes to elevated nutrient tanks either, common advice goes both ways with people running ULNS @ 11+dkh 1.027 sal and 450+  calcium and folks on the other end of the spectrum as well. My .02, since we can go beyond natural seawater and maintain those levels I really see no reason not to.

 

@OP, from my understanding of SPS and AI lighting in particular you need to turn your whites up, try to slowly ramp them up to near 20%. Oldschool mentality was that cool-whites 10000k to 15000k grew animals and bluer than that simply looked better to the eye. While this likely isn't totally-true, leaving out the white channel on the hydras is essentially giving up on 30+% of your light's PAR output, which is obviously far from ideal. That said the whites on these fixtures tend to be VERY PAR intensive and have a penchant, at least from community-experience, of easily-bleaching most animals when turned up too far past 35% or so.
You may want to try the AB+ settings for your hydra in acclimation mode over the next month and see if your colors return, it's by far one of the most popular-settings and pretty-well proven to grow darn-near anything.