HELP! Battling tissue necrosis of my SPS!

[sullivansp]

For the past 2 months, I have been dealing with slow tissue necrosis (STN) on many of the SPS in my tank. Multiple mini acro colonies (~4 in) have bitten the dust and I cannot figure out what is causing it to happen. Also, some SPS frags were also affected by STN while just one of them succumbed to RTN.

The following is some relevant information about my 90-gallon mixed reef:

History​

I inherited a 32-gallon Biocube from a family member in July 2018. This tank was running as a FOWLR for about a year. I transferred everything to a 45-gallon cube about 2 months later and then finally to a 90-gallon (48" x 22" x 24") in July 2020 (~9 months ago). So in total, this tank has been running for almost 4 years. Initially, I only stocked the tank with LPS/softies and was mostly successful. During the 2 years as a 45-gallon, the only corals I lost were 2 hammers. Once I upgraded to the 90-gallon, I slowly added SPS (mostly acros). I have seen decent growth on some and minimal growth on others.

Parameters*​

March 14, 2021 (2 days ago)

• Temp - 80.3 ºF
• Salinity - 1.026 SG
• Nitrate - 1.5 ppm
• Phosphate - 0.06 ppm
• Alkalinity - 11.9 dKH
• Calcium - 455 ppm
• Magnesium - 1600

March 3, 2021 (~2 weeks ago):

• Temp - 80.1 ºF
• Salinity - 1.025 SG
• Nitrate - 0.50 ppm
• Phosphate - 0.00 ppm
• Alkalinity - 12.1 dKH
• Calcium - 470 ppm
• Magnesium - 1650

*Test kits: Salinity - Milwaukee MA887 Digital Refractometer; Nitrate - Red Sea Nitrate Pro; Phosphate - Hanna HI738 ULR Phosphorous Checker; Alkalinity - Hanner HI772 Marine Alkalinity Checker; Calcium - Red Sea Calcium Pro; Magnesium - Red Sea Magnesium Pro

Lighting​

T5/LED combo:

• LEDs - (2) AI Hydra 32 (replaced one AI Hydra 26 about 3 weeks ago after it randomly stopped working)
• T5 bulbs - (3) ATI Blue Plus and (1) ATI Coral Plus (replaced one Coral Plus about 2 weeks ago with a Blue Plus [so previously was (2) Blue Plus and (2) Coral Plus])

Lighting Schedule:

• 12-hr photoperiod for LEDs (10am - 10pm with 2-hr ramp -up and -down)
• 7-hr photoperiod for T5s (12:30am - 7:30pm with no ramp)

Equipment​

• Skimmer - AquaMaxx ConeS-1
• Sump - Trigger Systems Rollermat 30 (~21 gal operating volume)
• Mechanical Filtration - Theiling Rollermat
• Refugium - chaeto w/ live rock rubble (Kessil H80 Refugium Light running reverse photoperiod [10pm - 10am at 75% intensity and 50% color])
• Powerheads - (1) Ecotech MP40 on left panel 2/3 up from bottom of tank [Reef Crest mode @ 65%]; (2) Ecotech MP10 on right panel offset 1/3and 2/3 up from bottom of tank [Lagoon mode @50% and Reef Crest mode @ 50%, respectively])

Maintenance​

Weekly-

• 10% water change using Red Sea Coral Pro salt (blue bucket)
• Empty Skimmer cup (usually more dry skimmate)

Monthly-

• Change carbon (Red Sea activated carbon, ~1 cup)
• Vacuum sand in DT and refugium
• Clean powerheads (as needed)

Dosing-

• Red Sea Reef Foundation (Calcium - 12 ml @ 12am; Magnesium - 5 ml @ 12am, Alkalinity - 32 ml @ 12am, 6am, 12pm, 6-m [8 ml each])

Livestock​

• ~40 lbs CaribSea life rock
• ~10 lbs regular live rock
• 50 lbs CaribSea Arag-Alive Fiji Pink sand (2 in sand bed)
• CUC - (1) large Mexican Turbo snail; (1) fighting conch snail; (2) emerald crabs; (~10) astrea snails; (5-6) blue- and red- legged hermit crabs; (5-10) nassarius snails; (5-10) cerith snails
• (1) Melanaurus wrasse
• (4) Ocellaris clownfish - (1) White Snowflake; (2) Wyoming White; (1) Black Snowflake
• (1) Coral Beauty Angel
• (1) Royal Gramma Dottyback
• (1) Exquisite Firefish
• (1) Helfrichi Firefish
• (1) Blood Red Fire Shrimp
• (2) Bubble-tip anemone
• Assorted Softies (large zoa colony, large ricordea mushroom colony, large toadstool mushroom, glove polyp, GSP, xenia)
• Assorted LPS (caulastrea, lobophyllia, frogspawn, torch, candy cane)
• Assorted SPS (acropora, stylophora, montipora, millepora)

Feeding: 3-4x daily (flakes, pellets, frozen); Reef Roids (2x weekly); Red Sea Reef Energy Plus (2x weekly)

One major issue that I think might be affecting my corals is in regards to my Alkalinity, Calcium, and Magnesium, which were all fairly low as of 8 months ago. I began slowly raising the levels from ~9 dKH (Alkalinity), 390 ppm (Calcium), and 1150 ppm (Magnesium) to where they are now over the course of those 8 months. I clearly raised the Calcium and Magnesium levels too high (especially apparent in my current Magnesium levels), with Calcium topping out at almost 500 ppm and Magnesium at around 1700 ppm. Around that time I also switched from Instant Ocean to Red Sea Coral Pro, but in anticipation of this move, I began dosing to slowly raise the Big 3 more in line with the Coral Pro salt. I did not break up my Alkalinity dosing until about 1 month ago, so I was essentially dumping around 25-35 ml of Alkalinity into my tank every night. Initially, I thought this was causing the tips of my acros to burn, but after remedying this by breaking up the dosing times into 4 daily increments, I am still noticing the same results- burnt tips and STN on many of the SPS. All of my softies and LPS are doing very well.

Hopefully I have included enough information in this post to assist in a diagnosis/ treatment of my predicament. Please let me know if I can provide any further information and thank you all! I look forward to your responses! Also, here are a few tank photos and I apologize if the coloring is off as I am still tinkerng with an app to capture the most realistic version of my tank.

 

[Spare time]

Your nitrate and phosphate are incredibly low for the alk you have. If you want high alk but ultra low nitrate and phosphate, you need to feed heavily (at least once a day with coral foods like reef energy). High alk promotes faster skeletal growth, but requires more food, flow, etc as you are essentially turbocharging the coral's skeletal growth. Having an ultra low nitrate and 0.00 phosphate level but high alk is a bad combo.

I would stop the water changes, feed the corals daily, and try to get nitrate and phosphate a little higher.

 

[USMC 4 LIFE]

Bring down your Alk slowly to 8.
Bring your CAL down slowly to 430
Bring your mag down to 1400.

You can let consumption of these parameters bring them down to each target level
And then maintain them there

 

[((FORDTECH))]

Both of the above opinions are good I second them

 

[sullivansp]

Your nitrate and phosphate are incredibly low for the alk you have. If you want high alk but ultra low nitrate and phosphate, you need to feed heavily (at least once a day with coral foods like reef energy). High alk promotes faster skeletal growth, but requires more food, flow, etc as you are essentially turbocharging the coral's skeletal growth. Having an ultra low nitrate and 0.00 phosphate level but high alk is a bad combo.

I would stop the water changes, feed the corals daily, and try to get nitrate and phosphate a little higher.

Thank you very much for the advice. I had come across a some similar information while reading up on my problem. I just wasn’t quite prepared to start altering nutrient levels until I had at least additional anecdotal evidence. What levels for nitrate and would you recommend? Say 10 ppm (NO3) and 0.15 ppm (PO4)?

 

[schuby]

I suggest that your SPS are starving to death due to your extremely low phosphate ( 0 - 0.03ppm) level. High alk with low nutrients causes burnt tips. Zero phosphate causes STN or RTN on SPS, regardless of alk level. Much safer to keep phosphate around 0.1ppm. Just my $0.02.

 

[sullivansp]

Bring down your Alk slowly to 8.
Bring your CAL down slowly to 430
Bring your mag down to 1400.

You can let consumption of these parameters bring them down to each target level
And then maintain them there

I really appreciate you’re advice. So if I do bring these parameters down then should I also change salts since the Red Sea blue bucket mixes at such high levels?

 

[((FORDTECH))]

I really appreciate you’re advice. So if I do bring these parameters down then should I also change salts since the Red Sea blue bucket mixes at such high levels?

Maybe and 10-15 nitrate and .08-.15 po4 is good

 

[sullivansp]

I suggest that your SPS are starving to death due to your extremely low phosphate ( 0 - 0.03ppm) level. High alk with low nutrients causes burnt tips. Zero phosphate causes STN or RTN on SPS, regardless of alk level. Much safer to keep phosphate around 0.1ppm. Just my $0.02.

Well I certainly do thank you for those $0.02. Based on all the feedback, my focus now will be balancing these parameters better.

 

[USMC 4 LIFE]

You can use the same salt. JUst ensure you do water changes in quantities that don’t drastically alter you’re water chemistry.

I use a salt (RPM) that mixes to my current parameters so very little adjustments if any are needed

 

[Deep]

I really appreciate you’re advice. So if I do bring these parameters down then should I also change salts since the Red Sea blue bucket mixes at such high levels?

The red sea blue bucket mixes at around 8. I think you are talking about red sea coral pro salt ?

 

[Buffalou]

First off thank you for the great detail in which you let everyone know what's going on and your issue. It's obvious you're in it to win it great write up. I have found that stability , stability, and stability is the most important aspect of keeping SPS. You had a pretty big swing in PO3 and NO4 in just a two week period. Additionally I agree with others bring parameters down slowly to acceptable levels. I have found ALK in the 9-10 range to be successful at the same time feeding 3-4 times a day with the frozen BRS fish food formula. I was dosing ,but now on a calcium reactor to provide greater stability, however I was successful when dosing. Last but not least you say everything was progressing along nicely up until two months ago think back as to what you may have done differently, water change shift? Salt change? Dosing more? Different lighting change ? Usually your SPS will let you know when they do and do not like certain things. I'm checking polyp extension everyday and do a once over really through examination of my tank to insure everything remains happy. Perhaps you changed something in your normal schedule and they don't like it. Hang in there my friend if it was easy it wouldn't be a challenge

 

[sullivansp]

The red sea blue bucket mixes at around 8. I think you are talking about red sea coral pro salt ?

You are correct. I am using Red Sea Coral Pro (NOT blue bucket) and mixes around 12 dKH.

 

[IslandLifeReef]

You are correct. I am using Red Sea Coral Pro (NOT blue bucket) and mixes around 12 dKH.

I would go back to the Alk, Calc, and Mag levels you had before when everything was happy. I understand trying to match the levels of your salt mix, but small water changes shouldn't cause an issue if they don't match. Living on the higher end of the Alk spectrum doesn't leave a lot of room for things to get out of wack without causing a problem IMO.

 

[sullivansp]

First off thank you for the great detail in which you let everyone know what's going on and your issue. It's obvious you're in it to win it great write up. I have found that stability , stability, and stability is the most important aspect of keeping SPS. You had a pretty big swing in PO3 and NO4 in just a two week period. Additionally I agree with others bring parameters down slowly to acceptable levels. I have found ALK in the 9-10 range to be successful at the same time feeding 3-4 times a day with the frozen BRS fish food formula. I was dosing ,but now on a calcium reactor to provide greater stability, however I was successful when dosing. Last but not least you say everything was progressing along nicely up until two months ago think back as to what you may have done differently, water change shift? Salt change? Dosing more? Different lighting change ? Usually your SPS will let you know when they do and do not like certain things. I'm checking polyp extension everyday and do a once over really through examination of my tank to insure everything remains happy. Perhaps you changed something in your normal schedule and they don't like it. Hang in there my friend if it was easy it wouldn't be a challenge

Thank you for the advice and encouragement! So the NO3/PO4 swing from 2 weeks ago is most likely from my attempt at overfeeding the fish. Both of these parameters have been hovering at or near zero for almost 2 years. I had always chalked that up to the chaeto growing at such a rapid rate and hogging all the NO3/PO4.

But I never noticed any sudden or widespread negative changes in my coral until the recent STN and after reading about other people’s experience with high alkalinity, I decided to try to raise them just a bit. However, I was unsure precisely how high to raise them until now.

Like you said I, have wracked my brain trying to think about what else could have caused this, specifically around two months ago. I am very consistent with weekly 10% water changes and always have been. No salt change or light change around the time this began. Just the dosing changes as described in the initial post, which were gradual and in accordance with Red Sea’s dosing recommendations (I never came close to even their maximum daily parameter change).

Honestly, the only thing I thought of was the weather change here in Houston. Around the first of the year, it finally got cold enough here in Houston to necessitate a few hours of warming for the water in my mixing station (which is in my garage) before performing water changes. I thought that maybe the longer mixing time was contributing to some funky parameter issues but testing never really reflected that concern.

Thanks again for your help and I will definitely consider dropping my alkalinity back down to the levels you mentioned, as well as trying the BRS frozen food formula as I have yet to try it.

 

[sullivansp]

I would go back to the Alk, Calc, and Mag levels you had before when everything was happy. I understand trying to match the levels of your salt mix, but small water changes shouldn't cause an issue if they don't match. Living on the higher end of the Alk spectrum doesn't leave a lot of room for things to get out of wack without causing a problem IMO.

Your recommendation seems to be part of the consensus on a solution to my problem. I have also heard about the tightrope that is high alkalinity and I think I am ready to get down! I really appreciate your input.

 

[Rmckoy]

Your nitrate and phosphate are incredibly low for the alk you have. If you want high alk but ultra low nitrate and phosphate, you need to feed heavily (at least once a day with coral foods like reef energy). High alk promotes faster skeletal growth, but requires more food, flow, etc as you are essentially turbocharging the coral's skeletal growth. Having an ultra low nitrate and 0.00 phosphate level but high alk is a bad combo.

I would stop the water changes, feed the corals daily, and try to get nitrate and phosphate a little higher.

I was thinking the same but 2 weeks prior nitrates were 50ppm

from 1.5ppm to 50 ppm in 2 weeks

 

[sullivansp]

I was thinking the same but 2 weeks prior nitrates were 50ppm

from 1.5ppm to 50 ppm in 2 weeks

Nitrates 2 weeks ago were 0.50 ppm not 50 ppm. Prior to that they were basically 0 for a long time. My Nyos test kit was hardly registering a color change so I switched to the Red Sea Nitrate Pro kit. It can detect low range values much better than the Nyos kit.

 

[Rmckoy]

Nitrates 2 weeks ago were 0.50 ppm not 50 ppm. Prior to that they were basically 0 for a long time. My Nyos test kit was hardly registering a color change so I switched to the Red Sea Nitrate Pro kit. It can detect low range values much better than the Nyos kit.

I apologize .
I miss read the original post .

 

[schuby]

Something I've observed in my tank is that SPS don't immediately change due to a large, stressful event. They usually show 1-2 weeks later. Once you notice your SPS looking poorly, look back a week or two for the trigger event.