Coral Decline Mystery – Need Insights!

[Qantos]

Hi fellow hobbyists!

I have a bit of a head scratcher with my 2.5-year-old reef tank. Started about a month back – some of my corals started losing tissue at the tips and others, especially my montipora and orange setosa, look to be badly bleaching or STNing.

Here's the rundown:

1. Heat Spike: One day about a month ago, the wife accidentally switched off the A/C. The tank temp climbed from the usual 78-79 to almost 81. By the time I got back a few days later, my large red dragon colony was history. It had RTN'd over the course of just a couple days. Some other corals looked pretty bothered as well but weren't showing any significant signs of trouble (reduced polyp extension mostly). Did a 30% water change, added some extra carbon, and tested the water. Most of it looked good, but phosphate had gone up to 0.40 ppm from 0.15 ppm a few weeks prior. I added some phosguard to slowly bring it back down. Currently sitting at 0.20 ppm.
2. Light Switch: In an effort to make sure something like this never happened again, I pulled the trigger and made the switch from halides to LEDs. My halides pump so much heat into the water which can be dangerous during these summer months. Kept the new LEDs at 50% power for about two weeks. But, it looked like the corals weren’t digging the change and slowly started declining. So, I went back to halides, thinking maybe the LEDs were too harsh in some spots and too dim in others. Fingers were crossed for some coral recovery.
3. Continued Decline: In the past two weeks, things haven't improved. I've been through tank troubles before – a winter blackout, low nutrients, dinos, AEFW, monti-eating nudis, and more. But this? Totally new. Some of my staghorn acros have dead tips but seem okay otherwise. Monti caps? Pale, splotchy, and even some diatoms on my red monti. Orange setosa is completely bleaching and/or STNing. And my usually very fluffy candy cane coral? Not so fluffy. Yet, for some strange reason, several of my most demanding acros are thriving.

Side note: During the LED time, alkalinity jumped from 7 dKh to 9.5 over the course of about a week. Maybe because the corals were stressed and not consuming so much? Been manually adjusting since then to keep it stable at 9 dKh.

I'll add a follow up post right now with some pics showing the corals that are in worst shape. If anyone's seen this before or has any pearls of wisdom, I'm all ears! Thanks!

 

[Qantos]

You can see some diatoms growing on my large red Monti cap.

 

[Maoiwowie]

I honestly dont think it is due to your heat spike to 81. Here in Los Angeles my tank can swing from 78 to 81 as the temps rise during the day almost every day . My sps have not shown stress because of those swings. And I run my LED (Neptune Sky) at 100% yet my acroporas cant seem to get enough light. But i do think something happened weeks ago or long before you actually started seeing issues; and here you are. My tank history wasnt without issues and i know ill have more problems ahead. Nature of this hobby. What i do when encounter problems is make sure water quality is pristine and levels acceptable, usually through daily/weekly water changes and the corals eventually improve. I stick with what I know and do not do anything else as I would be guessing. Could take weeks before things really improve. I make my own saltwater and never buy it from the store. I hope this helps.

 

[Qantos]

I honestly dont think it is due to your heat spike to 81. Here in Los Angeles my tank can swing from 78 to 81 as the temps rise during the day almost every day . My sps have not shown stress because of those swings. And I run my LED (Neptune Sky) at 100% yet my acroporas cant seem to get enough light. But i do think something happened weeks ago or long before you actually started seeing issues; and here you are. My tank history wasnt without issues and i know ill have more problems ahead. Nature of this hobby. What i do when encounter problems is make sure water quality is pristine and levels acceptable, usually through daily/weekly water changes and the corals eventually improve. I stick with what I know and do not do anything else as I would be guessing. Could take weeks before things really improve. I make my own saltwater and never buy it from the store. I hope this helps.

Thanks for the insight @Maoiwowie.
I tend to agree with you about the heat spike. It's not the first time my tank has shot past 80 degrees but it was odd timing because that was precisely when my red dragon colony RTN'd.

Ever since then the other corals started suffering as well. The only other thing I can think of was I did a series of water changes a week or two prior with a new bucket of Reef Crystals. I wonder if it's possible I got a bad batch... seems unlikely but can't think of anything else that changed around that time.

 

[billyocean]

Most likely not heat..81 isnt too bad. Stay the course and observe. Make sure your rodi is good to go and don't necessarily rely on a tds meter to tell you it's time to change media/membrane. Have you sent an icp to see if anything pops up? You mentioned monti worms..double check those...I'm sure you probably have

 

[Qantos]

Most likely not heat..81 isnt too bad. Stay the course and observe. Make sure your rodi is good to go and don't necessarily rely on a tds meter to tell you it's time to change media/membrane. Have you sent an icp to see if anything pops up? You mentioned monti worms..double check those...I'm sure you probably have

I don't think it is pest related. Many different species of SPS seem to be affected and they aren't showing the typical signs of pest damage. I have looked but not seen any.

You could be onto something with the RODI though. I haven't changed membranes in a while as my TDS still reads between 0 and 1. That's a good suggestion.

I also haven't sent in an ICP test. I'm from Toronto and it's a little more difficult to get those sent in from up here. I suppose that's the next step though.

Is the consensus that this is probably a water quality issue and not damage from LED burn or similar? I can't really tell if these corals are bleached or STNing but I'm leaning towards the latter.

 

[billyocean]

I don't think it is pest related. Many different species of SPS seem to be affected and they aren't showing the typical signs of pest damage. I have looked but not seen any.

You could be onto something with the RODI though. I haven't changed membranes in a while as my TDS still reads between 0 and 1. That's a good suggestion.

I also haven't sent in an ICP test. I'm from Toronto and it's a little more difficult to get those sent in from up here. I suppose that's the next step though.

Is the consensus that this is probably a water quality issue and not damage from LED burn or similar? I can't really tell if these corals are bleached or STNing but I'm leaning towards the latter.

Your p04 seems ok and I'm assuming your n03 is ok so I wouldn't think burnt tips or anything from low nutrients. I'm no light expert but depending on height and spread of the leds there could be some hot spots happening. As far as rodi it all depends on what you have to filter out from the tap. That's pretty much defense #1 in ensuring quality water so if it's been a while then a change wouldn't hurt. Let the membrane run off the appropriate amount of water when it's new before using the water and let it rip after that.

 

[blecki]

Was this AC the AC for your house? I don't think 81 degrees is a big deal, however if there was no air flow in the house you might have seen a PH drop.

Anyway, ruled out the possibility of coral warfare while you were away?

 

[Maoiwowie]

"Most of it looked good, but phosphate had gone up to 0.40 ppm from 0.15 ppm a few weeks prior." ... This bit sounds the most troubling to me. By the way i try to keep my PO4 between .03 and .10 using the Salifert test kit.

 

[ninjamyst]

Do you do any carbon dosing? Running any phosphate remover? I had the same thing happened to me. My montiporas were all dying. I stopped carbon dosing, removed phosguard, stopped doser, and just let the tank settle for 2 weeks. Now everything is fine. Turned back on dosers. Started carbon dosing again.

 

[PeterErc]

I had a frag system that I could not figure out why corals would not do well. One day was cleaning one of the tanks and found a penny in the sand. The kids would tape a penny on the end of a nerf dart. After penny was removed no more issues.
Have you checked pumps, magnetic scrapers, metal hose clamps or anything else that could be an issue.. People a while back had problems with MP-40 leaching.

Just a thought

 

[naterealbig]

Healthy corals won't blink at 2-3 degree temp change, especially topping out at 81.

My money is on alkalinity. Allow to drop to 8, and i bet your corals turn around. Many corals interestingly, can thrive in very low nutrients. Even many soft and LPS (that everyone will tell you are "high nutrient") corrals, but Montiporas will be your canary for this.

Say your test kit results, but i don't see a spec of algae growing in your display. Low available phosphate with higher alkalinity (9 or higher) and my Montipora (not zoas, not Acans, not Blastos, not cloves, not leathers) start suffering immediately.

Dying (bare bone) SPS tips are another sign.

While you're lowering alkalinity, dose aminos (and some Reef Chili and/or Reef Roids) to help tissue recover and add some bio-available phosphate.

 

[Cichlid Dad]

What led light did you switch to?.

 

[Qantos]

Thanks everyone for the feedback! I'll try to reply to each response here.

Your p04 seems ok and I'm assuming your n03 is ok so I wouldn't think burnt tips or anything from low nutrients. I'm no light expert but depending on height and spread of the leds there could be some hot spots happening. As far as rodi it all depends on what you have to filter out from the tap. That's pretty much defense #1 in ensuring quality water so if it's been a while then a change wouldn't hurt. Let the membrane run off the appropriate amount of water when it's new before using the water and let it rip after that.

I agree about the RODI. I've ordered replacement membranes and DI resin. This will at least give me peace of my mind on my water quality.

Was this AC the AC for your house? I don't think 81 degrees is a big deal, however if there was no air flow in the house you might have seen a PH drop.

Anyway, ruled out the possibility of coral warfare while you were away?

It was our home AC. Looking back at my Apex history, it doesn't look like pH saw a dip out of the normal range. No sign of coral warfare but could the quick RTN of the red dragon colony affect other corals in the tank?

"Most of it looked good, but phosphate had gone up to 0.40 ppm from 0.15 ppm a few weeks prior." ... This bit sounds the most troubling to me. By the way i try to keep my PO4 between .03 and .10 using the Salifert test kit.

I'm slowly bringing it back down to my normal range of 0.08 to 0.12 ppm. I don't like going much lower because I have a history with dinos. I think the high PO4 could be part of the problem, but not the major factor here just based on the way the corals are acting.

Do you do any carbon dosing? Running any phosphate remover? I had the same thing happened to me. My montiporas were all dying. I stopped carbon dosing, removed phosguard, stopped doser, and just let the tank settle for 2 weeks. Now everything is fine. Turned back on dosers. Started carbon dosing again.

No carbon dosing but I did start running Phosguard around the same time I switched to the LEDs. Could there be something in the Phosguard that is affecting the corals? I've heard rumours about aluminum leaching from this product but I thought that was a myth.

I had a frag system that I could not figure out why corals would not do well. One day was cleaning one of the tanks and found a penny in the sand. The kids would tape a penny on the end of a nerf dart. After penny was removed no more issues.
Have you checked pumps, magnetic scrapers, metal hose clamps or anything else that could be an issue.. People a while back had problems with MP-40 leaching.

Just a thought

This is something I've been considering as well. I had a look throughout my system and nothing jumped out to me. I'll need to disassemble my pumps and power-heads to be sure though.

Healthy corals won't blink at 2-3 degree temp change, especially topping out at 81.

My money is on alkalinity. Allow to drop to 8, and i bet your corals turn around. Many corals interestingly, can thrive in very low nutrients. Even many soft and LPS (that everyone will tell you are "high nutrient") corrals, but Montiporas will be your canary for this.

Say your test kit results, but i don't see a spec of algae growing in your display. Low available phosphate with higher alkalinity (9 or higher) and my Montipora (not zoas, not Acans, not Blastos, not cloves, not leathers) start suffering immediately.

Dying (bare bone) SPS tips are another sign.

While you're lowering alkalinity, dose aminos (and some Reef Chili and/or Reef Roids) to help tissue recover and add some bio-available phosphate.

My nutrients are pretty high. Phosphate had crept up to 0.40 ppm around when all this started but I've slowly brought that back down to about 0.20 ppm. Nitrate has been stable around 15 ppm. I do think you could be onto something with the higher alkalinity though. My alk normally sits around 7.0 dKh but rose to around 9.5 dKh over the course of about a week. Today it's about 8.5 dKh and I'll let it keep declining slowly to 8.

What led light did you switch to?.

Noopsyche K7 Pro V3 but I only ran those for a couple weeks before switching back to the halides. I thought it might be the lights causing my corals to stress out but since switching back to the halides things have continued declining.

 

[ocncheffy]

I can tell you that when my alkalinity is around 8.5 in my tank, ALL of my SPS start to develop burn tips. I cant explain why, but running at 7.5 has resolved that issue for me. This was with nutrients at the following:


Nitrate - 10
Phosphate .2
Mag - 1400
Cal - 420

 

[ninjamyst]

I would stop phosguard and see if things get better in a week. Montiporas recover fast under the right conditions

 

[naterealbig]

My nutrients are pretty high. Phosphate had crept up to 0.40 ppm around when all this started but I've slowly brought that back down to about 0.20 ppm.

Test kit brand?

 

[ScottB]

I had a few funky periods with my SPS that seemed to tie back to GFO. Never did a controlled experiment but the correlation was sufficient for me to stop using it. Dosed correctly, I feel more comfortable with lanthanum chloride. You have to be careful with it, but it is easier to dial it in.