Burnt tips / stn

[XavierZ06]

Just came back from a 2 week work trip, got some SPS that have been in my tank for 6 months that suddenly have burnt tips and some that have partially STN. Immediately ran tests but nothing standing out to me that would cause this.

Trident has maintained alk, cal and mag pretty steady the whole time, and I used HC to check accuracy.

Sg- 1.025
Po4 - .03
No3 - 50+ (should cause browning / color loss, not burnt tips, no?)
Alk - 9.1 (maintained 9.0 - 9.2 min/max for the last 3 months
Cal - 470 (bit high but stable between 450-470)
Mag - 1500

Don't think it's PAR related because it happened to coral on the sandbed as well as various heights of the rockwork. I'm kind of at a loss here. Any guidance appreciated.

 

[Dburr1014]

Just came back from a 2 week work trip, got some SPS that have been in my tank for 6 months that suddenly have burnt tips and some that have partially STN. Immediately ran tests but nothing standing out to me that would cause this.

Trident has maintained alk, cal and mag pretty steady the whole time, and I used HC to check accuracy.

Sg- 1.025
Po4 - .03
No3 - 50+ (should cause browning / color loss, not burnt tips, no?)
Alk - 9.1 (maintained 9.0 - 9.2 min/max for the last 3 months
Cal - 470 (bit high but stable between 450-470)
Mag - 1500

Don't think it's PAR related because it happened to coral on the sandbed as well as various heights of the rockwork. I'm kind of at a loss here. Any guidance appreciated.

From a seminar I went with Lou Ekus. Classic burnt tips. Raise your po4 and/or water charges to lower no3. I like po4 at minimum 0.05.

 

[jda]

That looks like polyp bailout to me.

Some SPS do not have any issues at all with no3 above 50, but many others will have issues ranging from quick death to slow decline. I would verify the nitrate test results and then work to bring those down.

Otherwise, go back to the basics and make sure that your temperature is checked with a mechanical tool, refractometer is calibrated, etc.

 

[vetteguy53081]

Looks like necrosis. Funny is, I too went to a tropic marin seminar several months ago.
Some possible triggers of infection are:
- Alkalinity spike
- Temperature spike
- Salinity spike
- Low dissolved oxygen
- Poor water quality related with phosphate levels up to 5 ppm
- Change in water flow
- Additions of sand
- Changes in brand of salt
- Bad test kits giving faulty results
- Levels of minor elements such as Iodine, Potassium, Strontium
- Light intensity
- Addition of new corals
- Pesticides
- Airborne Contaminants or sprays

A few things to check

 

[Som1else]

Definitely check your potassium levels too. I had something similar happen, all my other numbers were spot on. I lost quite a few colonies before figuring it out….the real sign was greyed out / dying monti’s and my gsp looked terrible and stoppped spreading.

 

[X-37B]

It looks like an alk or sg spike from the pics, imo.
Who watched the system for 2 weeks while you were gone?
No3 is way high for the po4 level you posted, imo.
The high no3 may have taken awhile to show this effect.
As long as the tank/fish are being properly fed your po4 is just fine.
I would look at why no3 is so high and make an adjustment to your export system.
How long has no3 been this high?

 

[XavierZ06]

Currently waiting for a 30% water change to finish mixing. Stopped dosing sodium nitrate.

Not sure how I missed this but the tank is currently fallow because velvet wiped me out 2 months ago, which is why I was dosing the nitrate. I'm assuming the po4 was also bottomed out for some time, and the corals might have been starved as there was no food going into the tank.

Ordered some reef roids to have something going in for them until ready for fish again, but not sure that would be root cause.

Triple checked test kits, and while there was a difference in the readings, they were consistent day over day (yest+today)/ test over test.

pH has been 8.1-8.3 with an oversized skimmer pulling in fresh air from outside the house, plus running through a CO2 scrubber.

 

[XavierZ06]

It looks like an alk or sg spike from the pics, imo.
Who watched the system for 2 weeks while you were gone?
No3 is way high for the po4 level you posted, imo.
The high no3 may have taken awhile to show this effect.
As long as the tank/fish are being properly fed your po4 is just fine.
I would look at why no3 is so high and make an adjustment to your export system.
How long has no3 been this high?

Wife is home with the tank, have no fish in there to feed, currently fallow. I have sodium nitrate being dosed, which must have been set too high. If I had to guess, it couldn't have been this elevated for more than a week or so.

Alk has had one spike to 9.4,16 days ago and was gradually brought back down to 9.0. aside from that spike, it has been 8.9-9.1 day over day.

 

[Dburr1014]

Wife is home with the tank, have no fish in there to feed, currently fallow. I have sodium nitrate being dosed, which must have been set too high. If I had to guess, it couldn't have been this elevated for more than a week or so.

Alk has had one spike to 9.4,16 days ago and was gradually brought back down to 9.0. aside from that spike, it has been 8.9-9.1 day over day.

Not enough of a spike to do anything, IMO.

 

[XavierZ06]

Not enough of a spike to do anything, IMO.

I thought so as well.

Temp has been 78-79.5 day over day. I have a heater with controller and the apex monitoring as well.

Recalibrated my hydrometer before testing salinity and it was still dead on. So that wasn't it. Ato has maintained that from an EVAP standpoint as well.

No water changes were done for the last 2+ months so no sudden changes there. Lights have been on the same program for 8 months.

 

[X-37B]

Wife is home with the tank, have no fish in there to feed, currently fallow. I have sodium nitrate being dosed, which must have been set too high. If I had to guess, it couldn't have been this elevated for more than a week or so.

Alk has had one spike to 9.4,16 days ago and was gradually brought back down to 9.0. aside from that spike, it has been 8.9-9.1 day over day.

What was no3 prior to being the current 50+?
A spkie to 50+ in a week may be the issue,imo.

 

[XavierZ06]

What was no3 prior to being the current 50+?
A spkie to 50+ in a week may be the issue,imo.

3 weeks ago it was near 0, it has been building up for 2 weeks I'd say. Just finished a 30% water change so I'll monitor no3 as I have the dosing stopped.

 

[jda]

With no fish, you could have had limited nitrogen to the acropora. Notice that I said nitrogen and not nitrate. Most acropora get their nitrogen from ammonia and it is not likely that they can use nitrate without massive energy costs and stressed corals cannot afford to spend that energy.

Once you get this sorted, if you are going to stay fallow, then I would recommend dosing ammonium and not nitrate. There is no coral in your tank that needs nitrate and few that can even use it - nearly all prefer ammonia/ammonium. Dr. RHF has a nice how-to in the chemistry section about dosing ammonia/ammonium.

Limited nitrogen and a spike in nitrate is the leading candidate, IMO.

If you want to dose nitrate, then anything above 2.0, or so, is not going to do anything for the corals that can use it. If you want to dose for other reasons, like to poison dinos, then higher levels might be needed, but this is different than for what corals can use.

 

[XavierZ06]

@jda definitely not going to continue fallow after I'm able to get fish back in. Have a few in QT right now waiting for July 15.

Tank is approx 160g total volume, and I've read through a whole bunch of threads since your comment. Didn't find a definitive answer on how much to dose over the course of the day, so if you can give a recommendation I'd sincerely appreciate it.

Is this the correct product or do I need lab grade stuff?

 

[jda]

Randy has some recommendations here.

DIY Ammonia dosing for low nitrate systems

I agree. That’s how I would define organic carbon dosing: adding an organic material that provides energy when it is metabolized. I’ve not calculated the energetics, but it may be low and not that useful for this purpose. Agree on definition. But then maybe urea could be organic carbon dosing...

www.reef2reef.com

 

[aznriceboi21]

That looks like polyp bailout to me.

Some SPS do not have any issues at all with no3 above 50, but many others will have issues ranging from quick death to slow decline. I would verify the nitrate test results and then work to bring those down.

Otherwise, go back to the basics and make sure that your temperature is checked with a mechanical tool, refractometer is calibrated, etc.