Nitrate levels

Lynn52 · Jan 30, 2016

I understand that there are two common ways of measuring nitrate. Some kits measure nitrate concentration and some measure nitrate nitrogen concentration which is about 1/4 of the nitrate concentration. I use a Salifert nitrate test kit which measures nitrate concentration. My nitrates are high, they were over 100 but are coming down slowly. Currently somewhere between 100 and 50. Both my ammonia and nitrites are 0. Temp is 78, SG is 1.025, Ca is at 420, Mg is 1240, and Alk is 8.5 dKH.
Initially I started looking at it when I lost a couple of apparently healthy fish and a couple corals. Since corals were affected as well I figured it was most likely the water not a fish disease. My maintenance had suffered for about 3 months after I had a series of kidney surgerys and was not allowed to lift more than 10 lbs. Water changes were less frequent and smaller. The problem came on slowly. Since mid December I have been working to reduce the nitrates by increasing the frequency of water changes to about every 5 days and changing 20 instead of 10% each time. It appears to be working.
My question is how do most people measure their nitrates? Do they use the nitrate concentration or the nitrate nitrogen concentration? Is my nitrate measured in the Salifert kit at between 50 and 100 as bad as I think since in units of nitrate-nitrogen it would be closer to between 12 and 25? I still need to get them down to much lower levels than they are but am I comparing the reading of my test kit to other people's levels that are actually a measurement of something else?

Randy Holmes-Farley · Jan 30, 2016

I'm very sorry to hear about your surgery.

Nearly all folks reporting nitrate levels on boards such as this are reporting ppm nitrate ion, not ppm nitrate nitrogen.

FWIW, I'm not convinced that the nitrate is necessarily the cause of all of the problems (even at 100 ppm), but it is certainly worth reducing it substantially.

There are many good ways of reducing nitrate aside from water changes. These include organic carbon dosing (including biopellets and soluble organics such as vinegar), various types of denitrators, growing macroalgae, algal turf scrubbers, skimming, etc. I compare emthods and give lots more nitrate discussion here:

Nitrate in the Reef Aquarium - REEFEDITION
https://www.reef2reef.com/blog/nitrate-in-the-reef-aquarium

I don't mean to be nosy about your medical issues, and feel free to not answer, but if you are on dialysis, you might get prescribed one of the drugs that I co-invented, the phosphate binders Renagel (sevelamer hydrochloride) or Renvela (sevelamer carbonate) to prevent hyperphosphatemia, which comes from chronic kidney disease, especially when on dialysis.

Lynn52 · Jan 30, 2016

Fortunately not on dialysis but one kidney is only working at 37%. I have very narrow pinched ureters and make stones that just can't pass. The doc essentially stretched the ureters and removed the pinched portions. One kidney at a time. I am fully recovered now. The goal was to prevent any further kidney damage.

I, too, am not convince that the nitrates are my whole problem but they are one I can measure. They were well above the detection limit of my salifert test kits initially so I really have no idea where they were in the beginning. I run GFO for phosphates and have been looking at vinegar dosing as an option to control the nitrates. I used to be able to grow chaeto in my sump but the last few months it just keeps dying, I have hair algae but it really isn't growing. My phosphates are undetectable so I thought that may be part of the chaeto issue. I have nitrates but no phosphates.

Randy Holmes-Farley · Jan 30, 2016

Lynn52 said:
Fortunately not on dialysis but one kidney is only working at 37%. I have very narrow pinched ureters and make stones that just can't pass. The doc essentially stretched the ureters and removed the pinched portions. One kidney at a time. I am fully recovered now. The goal was to prevent any further kidney damage.

I, too, am not convince that the nitrates are my whole problem but they are one I can measure. They were well above the detection limit of my salifert test kits initially so I really have no idea where they were in the beginning. I run GFO for phosphates and have been looking at vinegar dosing as an option to control the nitrates. I used to be able to grow chaeto in my sump but the last few months it just keeps dying, I have hair algae but it really isn't growing. My phosphates are undetectable so I thought that may be part of the chaeto issue. I have nitrates but no phosphates.

Yes, having low phosphate will reduce the effectiveness of export methods that use both, especially macroalgae. You might reduce the GFO for a while if you use vinegar or are trying to get the macroalgae growing again.

Lynn52 · Jan 30, 2016

Thanks, I'll try that. Need to get more chaeto. I ordered some from live aquaria but it was sent 2 day and came frozen solid. They will replace it and pay the shipping but I decided to wait till it is a bit warmer here in Minnesota.