Extremely high nitrate levels.

[Nick Barbier]

Hi fellow reefers, my 125g mixed reef has extremely high nitrate levels, over 200 ppm (not 20)! The tank is 10 years old. I tested the tank and couldn't believe the nitrate level. I brought a water sample to a LFS. They tested it and got the same nitrate level. This LFS suggested that I remove all the sand, increase dosing of NOPOX and start replacing the live rock slowly, one piece at a time. I took out half the sand and increased the NOPOX dosage. This didn't reduce the nitrate levels at all. At this point, I went to another LFS across town for a 2nd opinion. The manager told me that I shouldn't have gotten rid of any of the sand and that NOPOX is a carbon source and to stop dosing it. He then told me to do a massive water change, leaving only about 5 inches of water in the tank. The store owner told me to buy live nitrifying bacteria and start using filter socks. I left just enough water for the fish to swim around. I removed 63 gallons of water. I added a filter sock and added the bacteria according to the directions on the bottle.
I tested the water on a weekly basis for a month. The nitrate levels did not fall and are still over 200. Short of removing the live rock, half of which is about 15 years old and was transferred from my previous 75g reef tank, I've done everything two LFS instructed me to do. None of this worked. I have 8 fish in the tank and feed them 3 cubes of frozen food once a day which I also share with a 75g tank of 6 fish. I've lost most of the SPS and LPS corals. However, the softies seem to love the high nitrate levels. On a side note, I also had cyanobacteria which I have since pretty much eradicated using a UV sterilizer, a 4 day lights out period and Red Slime remover.
I don't know what else to do to lower the nitrate levels. Anyone that has experience/advice with lowering very high levels of nitrates, I would greatly appreciate your input.

 

[Randy Holmes-Farley Verified Community Expert]

The manager told me that I shouldn't have gotten rid of any of the sand and that NOPOX is a carbon source and to stop dosing it.

He's right about NOPOX being organic carbon dosing, but that isn't a reason to NOT dose it. That's why it is dosed.

There are lots of ways that will reduce nitrate given time and appropriate amounts, including the NOPOX.

Water changes are fast and good, but a pain and expensive on a 125 unless you use an automatic system. Nothing else is fast.

Growing macroalgae is useful.

A sulfur denitrator works, but depletes alk and is a bit tedious to run sometimes.

 

[gerards_reef]

I followed the advice and dosing schedule in the thread below and brought mine down from 350ppm ish to 25pm in around six months. I now employ a sulfur reactor to keep nitrates at my desired level of 25ppm. Didn’t change anything other than following the advice in the thread.

https://www.reef2reef.com/threads/new-vodka-and-vinegar-dosing-charts.1024056/

 

[Randy Holmes-Farley Verified Community Expert]

Why did he recommend nitrifying bacteria? Those are never needed on an established tank. They convert ammonia to nitrate.

 

[Nick Barbier]

He's right about NOPOX being organic carbon dosing, but that isn't a reason to NOT dose it. That's why it is dosed.

There are lots of ways that will reduce nitrate given time and appropriate amounts, including the NOPOX.

Water changes are fast and good, but a pain and expensive on a 125 unless you use an automatic system. Nothing else is fast.

Growing macroalgae is useful.

A sulfur denitrator works, but depletes alk and is a bit tedious to run sometimes.

One other thing that I forgot to mention. I also added a large bag of biomedical rings in the sump to help increase the nitrifying bacteria space.

 

[Nick Barbier]

I followed the advice and dosing schedule in the thread below and brought mine down from 350ppm ish to 25pm in around six months. I now employ a sulfur reactor to keep nitrates at my desired level of 25ppm. Didn’t change anything other than following the advice in the thread.

https://www.reef2reef.com/threads/new-vodka-and-vinegar-dosing-charts.1024056/

Isn't dosing NOPOX pretty much the same as dosing vodka and vinegar?

 

[Nick Barbier]

Isn't dosing NOPOX pretty much the same as dosing vodka and vinegar?

 

[Randy Holmes-Farley Verified Community Expert]

One other thing that I forgot to mention. I also added a large bag of biomedical rings in the sump to help increase the nitrifying bacteria space.

What exactly? I presume biomedical is a typo?

There's zero reason to think you need nitrifying capacity to increase.

maybe the LFS means denitrifying bacteria and space for them? That needs a different sort of material than one purely for nitrifying bacteria.

nitrifiers grow exposed tot eh open water. Denitrifiers (if any) willg row in low o2 regions deeper inside media or biofilms).

I know this isn't the place for it, and maybe I'll start a new thread, but the evidence that denitrification is an important process in ordinary reef tanks is not clear to me.

 

[Nick Barbier]

Why did he recommend nitrifying bacteria? Those are never needed on an established tank. They convert ammonia to nitrate.

Probably to out compete the cyanobacteria which I no longer have.

 

[Nick Barbier]

What exactly? I presume biomedical is a typo?

There's zero reason to think you need nitrifying capacity to increase.

maybe the LFS means denitrifying bacteria and space for them? That needs a different sort of material than one purely for nitrifying bacteria.

nitrifiers grow exposed tot eh open water. Denitrifiers (if any) willg row in low o2 regions deeper inside media or biofilms).

I know this isn't the place for it, and maybe I'll start a new thread, but the evidence that denitrification is an important process in ordinary reef tanks is not clear to me.

Sorry, biomedia. Stupid autocorrect!

 

[Nick Barbier]

What exactly? I presume biomedical is a typo?

There's zero reason to think you need nitrifying capacity to increase.

maybe the LFS means denitrifying bacteria and space for them? That needs a different sort of material than one purely for nitrifying bacteria.

nitrifiers grow exposed tot eh open water. Denitrifiers (if any) willg row in low o2 regions deeper inside media or biofilms).

I know this isn't the place for it, and maybe I'll start a new thread, but the evidence that denitrification is an important process in ordinary reef tanks is not clear to me.

The store owner sold me Microbe-lift special blend bacteria and bio-media rings for the bacteria.

 

[Randy Holmes-Farley Verified Community Expert]

Probably to out compete the cyanobacteria which I no longer have.

I doubt that nitrifying bacteria are likely to do that since the amount of food (ammonia) is fixed. More bacteria and same food doesn't seem like a recipe for bacteria competition with another bacteria (cyanobacteria).

But bottled bacteria contain all sorts of stuff, and perhaps other bacteria in it may prove helpful.

 

[Nick Barbier]

So, I'm a little confused. Should I not dose the NOPOX and continue dosing the Microbe-lift special blend? I don't think that the amount of food that I'm feeding the fish is creating the high nitrates, though I could wrong. Given the age of at least half the live rock in the tank, do you think that it could be saturated with nitates?

 

[coweyes298]

So, I'm a little confused. Should I not dose the NOPOX and continue dosing the Microbe-lift special blend? I don't think that the amount of food that I'm feeding the fish is creating the high nitrates, though I could wrong. Given the age of at least half the live rock in the tank, do you think that it could be saturated with nitates?

I was in similar situation as yours back in September last year. Tank is about 8 years old with FOWL, 100 gallon ish. Didn't pay attention to NO3 and PO4 since COVID and tested my NO3 last year it was off the chart over 75ppm, I guess it was in range of over 100 ppm. I started dosing vinegar last September and brought down my NO3 to 20 ppm ish at December. No water change no removing stuff from tank. I still feed heavily.

 

[Dan_P]

Hi fellow reefers, my 125g mixed reef has extremely high nitrate levels, over 200 ppm (not 20)! The tank is 10 years old. I tested the tank and couldn't believe the nitrate level. I brought a water sample to a LFS. They tested it and got the same nitrate level. This LFS suggested that I remove all the sand, increase dosing of NOPOX and start replacing the live rock slowly, one piece at a time. I took out half the sand and increased the NOPOX dosage. This didn't reduce the nitrate levels at all. At this point, I went to another LFS across town for a 2nd opinion. The manager told me that I shouldn't have gotten rid of any of the sand and that NOPOX is a carbon source and to stop dosing it. He then told me to do a massive water change, leaving only about 5 inches of water in the tank. The store owner told me to buy live nitrifying bacteria and start using filter socks. I left just enough water for the fish to swim around. I removed 63 gallons of water. I added a filter sock and added the bacteria according to the directions on the bottle.
I tested the water on a weekly basis for a month. The nitrate levels did not fall and are still over 200. Short of removing the live rock, half of which is about 15 years old and was transferred from my previous 75g reef tank, I've done everything two LFS instructed me to do. None of this worked. I have 8 fish in the tank and feed them 3 cubes of frozen food once a day which I also share with a 75g tank of 6 fish. I've lost most of the SPS and LPS corals. However, the softies seem to love the high nitrate levels. On a side note, I also had cyanobacteria which I have since pretty much eradicated using a UV sterilizer, a 4 day lights out period and Red Slime remover.
I don't know what else to do to lower the nitrate levels. Anyone that has experience/advice with lowering very high levels of nitrates, I would greatly appreciate your input.

Have you checked the nitrite level? Its presence can make it look like there is high nitrates. There might be high nitrates, maybe not that high.

The question for you is whether the system has a high rate of nitrate generation, for example, you are adding a large amount of food every day, or the system has a normal rate and is carbon limited which leads to the accumulation of nitrate over time. If the latter, perform a large water change and the problem is solved. If the former, you might have to take two approaches, knock down the nitrate level with a water change and increase nitrogen export by growing macro algae or carbon dose.

 

[Nick Barbier]

I was in similar situation as yours back in September last year. Tank is about 8 years old with FOWL, 100 gallon ish. Didn't pay attention to NO3 and PO4 since COVID and tested my NO3 last year it was off the chart over 75ppm, I guess it was in range of over 100 ppm. I started dosing vinegar last September and brought down my NO3 to 20 ppm ish at December. No water change no removing stuff from tank. I still feed heavily.

How much vinegar did you dose daily?

 

[coweyes298]

How much vinegar did you dose daily?

Based on the vinegar dosing chart, I started at 25 mil per day for few weeks and ramp to 60 ml, them 80 ml, finally end up at 100 ml. Took me 2 months to see the NO3 drops from over 75 ppm to 17 ppm.
Spread the total daily dosage to multiple small dosage along the days.

 

[legionofdoon]

I'm running an Aquamaxx TS300 and honestly it's the fastest and easiest way to lower nitrate I'm about a month in and mine lowered my nitrates from 75+(Hannah won't go over 75) to 11.6. They aren't tricky at all but you have to use enough sulfur. I'm using 15 lbs in mine. Running around 70ml a minute. Just get a PVC needle valve, before I got that dialing it in was a nightmare. My tank is around 100 gallons total.

 

[legionofdoon]

I did have to start dosing alkalinity.

 

[Kelly Cooper]

Based on the vinegar dosing chart, I started at 25 mil per day for few weeks and ramp to 60 ml, them 80 ml, finally end up at 100 ml. Took me 2 months to see the NO3 drops from over 75 ppm to 17 ppm.
Spread the total daily dosage to multiple small dosage along the days.

Straight vinegar?