STN - :( no bueno

[MikeTR]

So i'm at a loss here. Too many factors to pinpoint the problem so I'm just sitting back and watching coral waste a way. New tank? Parameters? Salt mix? Light too strong? Temp fluctuations? Gah! I'll explain each factor and maybe someone can turn me on to a fix.

180g tank

Params: (no dosing)
Alk 7 (Red Sea & API)
Calc 500-540 (Red Sea - API)
Mag ?
Phos - .08 (Hanna digital)
NO2 - 0 (API)
NO3 - 0 (API)
NH3 - 0 (API)
Temp - 77.4 - 79.5

All these corals were ok in my frag tank which were under 150w halides at about 12" depth. Corals in question, various birdsnests, various monti caps, stylophora, purple polyp scroll, undata, encrusting monti..

Salt is TM Bioactif. Tank has reached it's 4 month mark. Corals were put in just 2 weeks ago.

Temp controlled by a chiller. Takes about an hour to heat it to 79.5 and about 2 hours to cool it back down to 77.4 when lights are on. Cools down in 45 minutes if lights are off. Is the temp swing too fast?

Lighting 3 x 250w radiums. Lighting too strong? Caps in the back are getting about 150 par. Birdsnest about 300 and are in lower 1/3rd of tank. Undata is at the bottom, still about 250-300 par. Most everything is on the sand or lower 3rd of the rock.

 

[Dexters Reef]

I too am battling STN on one of my acros...it was doing fine 2 months ago, but in the last two months I had no polyp extension at all, and started developing STN in some areas. No parameters have changed.

I looked at some pics of my tank 2 months ago when it was opening, and noticed a lot of my SPS colonies have grown in a lot, and noticed corals were not swaying as much as they were before. My theory was that the new growth has been impeding flow, and my one SPS was not extending polyps to conserve energy, and was slowly starting to waste away as a result.

Two days ago, I removed a Hydor 1400GPH powerhead and replaced it with a MP40. To my surprise, 6 hours later, I had 50% polyp extension on the entire coral that hadnt opened in 2 months. Im hoping the new additional flow (plus randomness that it generates) encourages the coral to continue to extend polyps, feed and eventually heal.

I also dipped it to rule out pests, found nothing. Now, its only been 2-3 days for me, but the new polyp extension is a good sign. I'm hoping its not too late to save it, the majority of the coral looks great, just STN by the base and a little on its side.

So my advice is to look into flow. What kind of powerheads are you using? How many? How would you compare the flow between the frag tank and the display tank?

Maybe take one out and put back in the frag system to see if it recovers? Any fish or creatures that might be nipping?

 

[MikeTR]

I have 2 MP40s on reef crest at 75% and a reeflo dart return pump.

 

[MikeTR]

Stocking list:
2 yellow tangs
purple tang
hippo tang
bellus angel
2 clowns
royal gramma
coris wrasse
lubbocks wrasse
ruby head fairy wrasse.

 

[MikeTR]

Skimmer is SRO3000 EXT. Filter socks. As far as equipment goes, it's pretty much all high end stuff.

 

[MikeTR]

Lighting is only on for 4 hours at the moment also. I've had no algae build up on the glass in a week. Feeding every day to try and get a little bit. Chaeto died out in the sump. First couple days the skim was pretty dark. Now it's just tea colored with peanut butter (yum) in the neck.

 

[Sugar Magnolia]

Your alk is on the very low end of the recommended 7-11 dKH. Try to bump that up to arroun 9 or 10. Also, it would be wise to get a mag test kit. Mag regulates alk and calc.If your mag is low then it's difficult to raise the other parameters.

My other thought is your temperature fluctuation. Is there a reason you aren't keeping it at a constant 78-79 temp? 77 is on the low end of the optimum temp range of 76-83.

Have a look here at recommended water params - http://www.reefkeeping.com/issues/2004-05/rhf/index.php

In order to stop the STN you'll want to remove the affected colonies/frags so it doesn't spread to all of your SPS. Doing a profolactic dip in some Lugol's or some kind of coral disinfectant may help as well.

Edit: Why are you only lighting for 4 hours a day?

 

[MikeTR]

It's not just receding from the base either like I've seen when alk is low. It's almost like RTN, but it's not fast enough as that usually takes them in a matter of a few days if not overnight. Some of the areas look like they'd be unreachable in the birdsnests to nippers.

 

[MikeTR]

Working on the alk with baking soda and possibly going to switch salt brands. Instructions in the tradewinds chiller say not to make the differential lower than 2 on the Ranco controller. I have a set point of 77 with a differential of 2. I'd really like it to be a 1 degree swing actually so maybe I'll change the differential to 1 and just keep an eye on the temp and see how long the chiller runs. I'm thinking 78-79, or even 79-80 is better. Lighting was originally reduced to 4 hours to not spark up an algae bloom. I left it at 4 hours and was going to add an hour each week to acclimate the new additions, but when I saw this happen I figured additional time would make it worse.

Going back to the differential setting.. it says that if the differential is at 1, then it would be a .2 deg change and would cycle the chiller too fast.. though if that was true, then a differential of 2 would be 1.2 and not 2 degrees like i'm seeing.

 

[rrasco]

I've been battling the same thing over the last two months. On two different occasions I lost:

-stubor colony and hollywood stunner
-stubor colony and birdsnests started showing signs, along with my red planet

First time was alk crashing from 9-7dkh when I switched to kalk (back on 2-part). The other time I dosed mag and I don't know if I mistested or overdosed, but it was only supposed to raise it 100ppm but it jumped from 1200-1400ppm and then I noticed issues. I guess stubors are pretty sensitive since they seem to be the most affected in my tank with these swings. Seems like it takes 3-4 days for it to stop receding, typically when the whole colon is almost gone. Good thing is they can recover if you stabilize the system.

 

[Dexters Reef]

I would say the alk is a little low, along with flow. I have 1 MP40 on my 75 at the moment, and another 1400 gph koralia. I easily can admit I need another MP40. If I had the other MP40, I feel my tank would have ideal flow, and its less than half the size of your tank.

ReefCrest is a great mode, but it spends a lot of its time below 50%. So if a MP40 does 3200GPH on max, and you are running it at 75% Reefcrest, then the MOST each will hit is 2400 GPH. So if BOTH mp40s happen to be on full blast at the exact same time, thats 4800GPH which is a 26x turnover...a little on the low side but not terrible. But since Reef Crest has a lot of time under 50%, each powerhead is then putting out somewhere around 1200 gph, which gives you about 2400 GPH combined, which is only a 13.3x turnover.

These numbers are estimates, and just quick numbers off the top of my head, but I would suspect that you dont have enough water movement. A lot of people run dual MP40's on 75 and 90G tanks, and for a 180, I think MP60s are needed, or more MP40's

 

[MikeTR]

OK so alk is up in the mid 8's. Calc still holding at 500. I've upped the time to 5 hours on the lighting. At this point it's probably not the lights. I can't see that lack of flow would toast the frags in just a couple weeks so it's gotta be parameters at this point. Maybe the the change in calcium, the frag tank calc had dropped to 380. Alk was running a little lower too. I did slack off on water changes on the frag tank the last month as I knew it would be coming down. Could've been the downfall here moving them all from a dirtier tank to a cleaner system. Green slimer, blue (browned out) milli, hawkins frags are still hangin in there with no signs up decline.

 

[CHSUB]

4 months, imo, is too early for sps. API tests kits are not sensitive enough to give reliable data on a tank that young. zero on any reading you get with an API tester is enough to harm sps's...wait another 4-5 months!

 

[dg3147]

I've been though the same thing with 2 different tanks. I think that 4 months may just be too soon for sps. Once one gets STN, it seems to spread to all of them. My theory is that a dying sps affects the others or some sort of early tank syndrome.

If u are anxious to stock the tank, go with some LPS and poyps...then add sps around the 6-12 month mark. These corals do well with early tanks (though, may not thrive as you optimize for sps down the road, so dont stock them too heavy).

 

[dg3147]

I've been though the same thing with 2 different tanks. I think that 4 months may just be too soon for sps. Once one gets STN, it seems to spread to all of them. My theory is that a dying sps affects the others or some sort of early tank syndrome.

If u are anxious to stock the tank, go with some LPS and poyps...then add sps around the 6-12 month mark. These corals do well with early tanks (though, may not thrive as you optimize for sps down the road, so dont stock them too heavy).

 

[Reefin' Dude]

how long has the tank been setup? do you have a substrate? how often was it cleaned of detritus? i would assume that the SPS are STN'ing from their bases?

the only reason why alk should be kept above NSW levels is because you are fighting the bacteria "processing" phosphates that are using up the alk for an available carbon source. keeping high alk and Ca levels does very little for coral growth and in fact pushes corals towards STN by amping up their metabolism and making them more susceptible to disease and other stressors. i have found little reason to run alk above 7 and Ca above 400.

if your corals are turning brown. that is another indicator that you have a phosphate problem with SPS. the coral is not longer in charge of the nutrient supply to the zoax. the zoax are getting any free phosphates they want from the water column itself. producing more zoax.

G~

 

[MikeTR]

This is turning out to look more like RTN. Took a few days for it to start, but tissue is sloughing off. Gotta be parameters or bad batch of salt. Starting to see some polyp bailout on some Caulastrea also.

 

[rrasco]

Whenever I get STN/RTN it doesn't affect the whole tank. In fact, only one or two corals react to the conditions.

I am not 100% on this, but from what I understand STN can take a coral in a few days. RTN happens in a matter of hours. Mine usually took 4-5 days to recede completely. I'm talking about a 6-7" colony.

 

[MikeTR]

Found the culprit. Nitrates are at 50 when tested using Salifert kit, which I bought. Still reading as yellow as ever with API.. which is now in the garbage. Since my chaeto was dying out and relatively no algae growth on the glass I figured I needed to get some nutrients goin.. so I've been feeding every day to try and get a nitrate reading.. Well I succeeded. Son of a ... also as a result my phosphates have jumped to .55.

 

[karsseboom]

A lot of misinformation going on here. First off your alk is totally fine at 7 you will have the se growth and colors at dkh of 9. Second I don't think your temp swings are too terrible but I thing 5 degrees swings are at the max. Third if your po4 is high it would only cause problems if it rose to fast but at your levels it seems fine. Running your lights has nothing to with your problem and 4-8 hours of lighting is acceptable with 5-6 being perfect in IMO. What I would do is start dipping the Sps look for pest or maybe se contaminate got into your system, double check your salinity, double check all the test kits and start thinking about all the changes you may have done.