SPS problems

I just started adding SPS recently and it has not been going so well. I currently have three acro colonies and a giant red montipora capricornis. The monti and one of the acros are growing some sort of black fuzzy algae around them. I assume its algae anyway, because my sailfin tang has been picking at it non stop. I have tried to ramp up the flow on these colors, but the capricornis starts to break off into pieces. I normally have pretty high flow on them though. The corals have maintained great color, but the polyps are receding.
Another problem I'm having is with an acrpora digitata that I bought from Diver's Den. This thing has been brown since the second I put it in my tank. The flow on this one is also very high and I have just moved it higher up to get it more light. Could it just be that the zooxanthellae are just flourishing because of the low phosphate levels in my tank? What else can I do to help it regain its deep blue coloration?
I had a small millepora colony RTN a few days before I added these new SPS. Is this something that could have stuck around and spread to these new corals?

Tank specs:
150g mixed reef w/ 11 fish. Have kept many softies and LPS with no problems
Ecotech Radion led lighting, 30 gallon refugium-style sump, 170-200 lbs live rock, uv sterilizer, skimmer, three 1400 gph ph's + two return pumps

My levels are:
Calc-430
Dkh-8 (slowly raising this w/ soda ash)
ph-8.0
phosphate-.03
amm/nitrite-undetectable
nitrate-undetectable

Thanks in advance to anyone that can help solve my SPS issues.

 

Welcome to 3reef,

I can not address the lighting but did you acclimate the corals to the lighting?

Did you change lighting?

Bringing the alk up should be of assist as long as you maintain it and make sure swings are not too drastic.

Perhaps post a image of the tank or corals.

Are you feeding the tank in any way, as in feeding the fish and LPS.

Are you running any bio-pellets?

Have you checked for pest such as Acropora eating flatworms, Red Bugs?

Welcome to 3reef BTW.

 

Thanks

I did briefly light acclimate them with the Radion's light intensity functions, but I figured my one browning acro needed higher light soon. The capricornis could be under too intense lighting but I'm not sure why that would cause the black fuzzy stuff.

The acros were moved from 400w metal halides to my radion's natural program. I'm not sure what the monti was under before.

I feed two-three times a day with a lot of dif, frozen foods: mysis, brine, squid, cyclops, and emerald entrees (also includes different algaes, krill, microplankton). The Lps get frozen mysis about once a week.

No bio-pellets

I have seen flatworms in my refugium but they are not in the main display as far as I know.

I'll work on getting a pic up

 

Update-
This is most definitely an RTN event. One branch of my acro has turned white and its expelling a lot of black stuff. How can I stop this from happening?

 

if it is rtn'ing then frag it. Cut above the healthy part to save part of the colony. I didnt see it listed but what is your Mag at? and salinty?

 

Got it. thanks. Sg is 1.025 and magnesium is unknown.

What exactly is RTN? Is it a disease that can spread throughout my tank?

 

RTN (rapid tissue necrosis), the tissues literally falls off the skeleton.

It's a symptom of a primary problem. It can be parameters, disease......

When you say that black stuff is coming off or out of the corals that is odd and almost sounds like the corals are dumping their Zooxanthellae.

The only other black I can think of is sometimes Cyanobacteria.

Maintaining the blue coloration to Acropora is difficult. It requires nutrient free water and very intense lighting.

I wish I knew more about your lighting, I have no experience with LED's though.

 

Hmm. Scary situation, thats for sure. Test for magnesium levels. I would suspect that they are low. Magnesium is often overlooked, but it is very important. What brand salt do you use? And only your SPS are affected? You other corals look fine? What did you use to test for your Alk, Cal, and PO4 numbers? The brand test kit does make a difference.

 

I'm not sure it's RTN from this description. Expelling black stuff sounds like expelling zoox to me, which would result in bleached corals. How did they turn white, by loosing tissue (RTN) or by expelling through the polyps (bleaching)? Do you only see the coral skeleton now or is the skeleton skill covered in white tissue & polyps?

So three things to keep SPS (mostly) happy: flow, lighting, and parameters. Sans Mg numbers, your parameters look fine. What test are you using to measure PO4? Elevated phosphates could explain bleaching/browning. Your lighting is complete capable of sustaining SPS, but you make a mention of a "natural program". What do you mean by this? How much intensity do you have the light turned to, and how long are you running it per day? Lastly, while you may think you have a lot of flow, you actually sound short in it to me. 3 1400's in a 150g tank isn't much for SPS, but you didn't provide flow of the 2 return pumps you're using. What are they and how are you using them?

The only other variable in this is pests. It is entirely possible you have MEN (montipora eating nudibranches), AEFW (acro eating flatworms), Red bugs, or some combination of any/all of the above, which would complicate things here. Did you dip or QT any of these corals? You might want to research the three pests listed above, and see if you have any signs of them. Flat worms in your sump need not apply; there are hundreds of different species of flatworms, and each is rather particular in diet. Same applies for nudibranches.

 

The Natural program replicates the sun...starts off around 10% and hits 100% for a "high noon" effect. For reference, I ran mine no higher than 60% whites for 4 hours per day, 8" from the water.