Nitrate issue after fish death

[dmanning]

Hi All,

My current reef tank is currently 4.5 years old and is a mix of LPS and SPS. All very healthy and happy until 3 weeks ago.

Tank is a Red Sea Reefer 350, and water chem before the incident was as follows:
-Alk: 11.1dkh
-Cal: 510ppm
-Mag: 1380ppm
-PH: 7.66
-Ammonia: 0ppm
-Nitrite: 0ppm
-Nitrate: 7.4ppm

Three weeks ago I had my 7 year old wrasse pass away and found him half eaten in the corner of the tank. (May have been in there a few days)
I checked nitrates immediately and was over max reading of 50ppm. I did a 30% water change that day, then another 30% the next day.
But damage had been done and I lost 3 large sensitive SPS colonies in the next 12 hours.

Tested nitrates again and the are back to 48ppm due to SPS RTN.

So twice a day for 5 days i did a 20% water change and got nitrates down to 22ppm.
But now 3 days later nitrates are back to 43ppm.

I cannot locate the source of the nitrates, so looking for ideas on how to lower nitrates back to previous levels.

I am already doing the following:
-dosing 7ml no pox per day
-have healthy Marco algae in the sump
-have skimmer running wetter than normal
-have reduced fish feeding to half previous rate
-have vacuum syphoned all reachable coral sand
-have increased flow in the tank to help suspend particles (I have crazy high flow capacity)

Any ideas would be very welcome.

I included a photo of my tank post SPS loss, most coral is still very happy. But nitrates are still over 40

 

[kharmaguru]

Hi All,

My current reef tank is currently 4.5 years old and is a mix of LPS and SPS. All very healthy and happy until 3 weeks ago.

Tank is a Red Sea Reefer 350, and water chem before the incident was as follows:
-Alk: 11.1dkh
-Cal: 510ppm
-Mag: 1380ppm
-PH: 7.66
-Ammonia: 0ppm
-Nitrite: 0ppm
-Nitrate: 7.4ppm

Three weeks ago I had my 7 year old wrasse pass away and found him half eaten in the corner of the tank. (May have been in there a few days)
I checked nitrates immediately and was over max reading of 50ppm. I did a 30% water change that day, then another 30% the next day.
But damage had been done and I lost 3 large sensitive SPS colonies in the next 12 hours.

Tested nitrates again and the are back to 48ppm due to SPS RTN.

So twice a day for 5 days i did a 20% water change and got nitrates down to 22ppm.
But now 3 days later nitrates are back to 43ppm.

I cannot locate the source of the nitrates, so looking for ideas on how to lower nitrates back to previous levels.

I am already doing the following:
-dosing 7ml no pox per day
-have healthy Marco algae in the sump
-have skimmer running wetter than normal
-have reduced fish feeding to half previous rate
-have vacuum syphoned all reachable coral sand
-have increased flow in the tank to help suspend particles (I have crazy high flow capacity)

Any ideas would be very welcome.

I included a photo of my tank post SPS loss, most coral is still very happy. But nitrates are still over 40

I think you have it all covered frankly and just have to wait assuming there is no more RTN. Many successive water changes could be just as unsettling to SPS as high nitrates IMO unless you are matching all your values.

 

[Reefing102]

Do you have anything in there that consumes nitrates at a higher like macro algaes?

 

[dmanning]

Do you have anything in there that consumes nitrates at a higher like macro algaes?

Yep in the sump, 2 different types.

 

[dmanning]

I think you have it all covered frankly and just have to wait assuming there is no more RTN. Many successive water changes could be just as unsettling to SPS as high nitrates IMO unless you are matching all your values.

Yeah I made sure values matched including salinity and temp. I didn’t want to shock them more by suddenly changing PH or Alk

 

[dmanning]

Well I finally solved the problem.

I installed a Bubble Magus Roller Filter ARF to replace my double filter sock configuration. 2 rolls of filter material later and im sitting pretty at 7ppm and still dropping 1.5ppm per week.

​

 

[Vinny Kreyling]

I would NOT let it go lower than 5ppm.
5-10 is OK.

 

[Reefing102]

Agreed. I’d see if you could stabilize it as low nutrients are believed to cause algae issues as well as coral health issues