Good ways to reduce NO3

[ReeferAdrian]

Hey guys,

Am wondering what are the solutions or ways you have tried to successfully reduce NO3? I have been doing frequent water changes but the Nitrate level still hovers around 60ppm. Tank has been running for 9 months now.

Was thinking of adding in SeaChem Stability and SeaChem Matrix to cultivate more bacteria, will this work over time (not expecting instant results)?

Thoughts?

 

[250mixreef]

carbon dosing with vinegar worked for me

 

[TbyZ]

algae scrubber for NO3 & PO4

 

[stevo01]

Vacuum out overflow, sandbed, and sump.

 

[Salty1962]

What is your livestock? Do you have a skimmer? Is it working correctly? Do you run any carbon?
I would cut back a bit, you gauge best by your tank, on feeding the tank. When doing WCs, take a turkey baster and blow your LR off and then siphon out the debris. Keep your styrofoam clean if you use it.
I would try these things before you go the carbon route, it can strips the nutrients very quickly. Give the above a try and see how it goes,

 

[Salty1962]

algae scrubber for NO3 & PO4

+1 I use the TurboAquatic's L4 on my 65G, and my No3 is @4-5ppm.

 

[Orm Embar]

https://www.reef2reef.com/ams/nitrate-in-the-reef-aquarium.10/

Having said that, I swear by macroalgae (main tank and refugium). If you have a sump with space for it, it's cheap/easy/effective. Other people go the carbon dosing/GFO route. Skimmers and filter socks rinsed twice weekly can also remove a decent chunk (20-35% removed disslved organics from skimming which would decompose; filter socks rinsed twice weekly or more per BRS video can lead to a 30% reduction as well).

Mathematically, partial water changes seem like a losing battle that's a lot of work on top of it all.

.

 

[Randy Holmes-Farley]

The article linked above describes lots of different ways to reduce nitrate.

 

[ReeferAdrian]

I am currently running a skimmerless system, and as such i heard vinegar and carbon dosing needs a skimmer to be effective. As for algae scrubber, will look into that, seem like its quite effective coming from you guys.

Currently i have chaeto in my main tank, started it off last week, hopefully am able to see some kind of reduction in NO3.

At the same time, i went ahead and got myself Seachem Stability and Matrix yesterday, and i will keep everyone posted on the results.

And thanks Orm and Randy, that is a good article. Seems like while nitrate is the "least" deadly as compared to the older brothers, Ammonia and Nitrite. Still I am worried long term wise, on the health of both fish/inverts and corals.

 

[Randy Holmes-Farley]

I am currently running a skimmerless system, and as such i heard vinegar and carbon dosing needs a skimmer to be effective.

I'm not sure you "need" a skimmer. That's more of a hypothesis than a proven fact/idea.

 

[TbyZ]

I'm not sure you "need" a skimmer. That's more of a hypothesis than a proven fact/idea.

Doesn't a skimmer remove the water column bacteria (that has proliferated due to the dosed carbon) that has taken up n & p?

 

[Randy Holmes-Farley]

Doesn't a skimmer remove the water column bacteria (that has proliferated due to the dosed carbon) that has taken up n & p?

That's the theory, and I'm sure it happens to some extent when you add organic carbon and also skim. But is skimmate the only sink for the N taken up when carbon dosing? Almost certainly not. Is it even the primary one? I don't think we have any data to answer that.

1. Many organisms can use the dosed carbon directly, and may grow faster because of it. Most of these organisms are benthic and not skimmable. Corals, sponges, even some types of algae.

2. There's a whole food chain above bacteria that can consume the bacteria and thereby take up some of the N and P from the bacteria. Many of these are too small to skim.

The question is what happens if you add organic carbon and do not skim. A few folks have tried or are trying this, but I've not heard back much in the way of results. It could be that the mechanisms 1 and 2 above simply expand in importance.

 

[TbyZ]

That's the theory, and I'm sure it happens to some extent when you add organic carbon and also skim. But is skimmate the only sink for the N taken up when carbon dosing? Almost certainly not. Is it even the primary one? I don't think we have any data to answer that.

1. Many organisms can use the dosed carbon directly, and may grow faster because of it. Most of these organisms are benthic and not skimmable. Corals, sponges, even some types of algae.

2. There's a whole food chain above bacteria that can consume the bacteria and thereby take up some of the N and P from the bacteria. Many of these are too small to skim.

The question is what happens if you add organic carbon and do not skim. A few folks have tried or are trying this, but I've not heard back much in the way of results. It could be that the mechanisms 1 and 2 above simply expand in importance.

Since most of us try hard to remove DOC from the aquarium I don't understand why anyone would dose it intentionally.

 

[Randy Holmes-Farley]

Since most of us try hard to remove DOC from the aquarium I don't understand why anyone would dose it intentionally.

You mean like vinegar?

The DOC and POC we remove often contains N and P, and often is not as readily taken up or metabolized as something such as acetate from vinegar. Some may be outright toxins. Some bind heavy metals such as copper.

The acetate from vinegar contains no N or P (or any other element besides C, H, O), and is not likely toxic to anything at the doses we provide.

 

[TbyZ]

You mean like vinegar?

The DOC and POC we remove often contains N and P, and often is not as readily taken up or metabolized as something such as acetate from vinegar. Some may be outright toxins. Some bind heavy metals such as copper.

The acetate from vinegar contains no N or P (or any other element besides C, H, O), and is not likely toxic to anything at the doses we provide.

So if vinegar is dosed to an aquarium without a skimmer, would it be dosed at the same rate, &, wouldn't GAC remove it quickly in any case?

 

[Randy Holmes-Farley]

So if vinegar is dosed to an aquarium without a skimmer, would it be dosed at the same rate, &, wouldn't GAC remove it quickly in any case?

GAC won't bind acetate from water (acetate is too hydrophilic), nor is it skimmed. Like any tank, I'd adjust the dose by trial and error to what seems to benefit the tank.

 

[stevo01]

Great conversation here!

 

[Dennis Cartier]

That's the theory, and I'm sure it happens to some extent when you add organic carbon and also skim. But is skimmate the only sink for the N taken up when carbon dosing? Almost certainly not. Is it even the primary one? I don't think we have any data to answer that.

1. Many organisms can use the dosed carbon directly, and may grow faster because of it. Most of these organisms are benthic and not skimmable. Corals, sponges, even some types of algae.

2. There's a whole food chain above bacteria that can consume the bacteria and thereby take up some of the N and P from the bacteria. Many of these are too small to skim.

The question is what happens if you add organic carbon and do not skim. A few folks have tried or are trying this, but I've not heard back much in the way of results. It could be that the mechanisms 1 and 2 above simply expand in importance.

Actually a somewhat well know method uses this exact format. The DyMiCo filter that is being sold in Europe uses carbon dosing and no skimmer. Their reasoning is that the skimmer removes too much of the zooplankton and allowing a robust food web to develop benefits the higher form inhabitants more than what the skimmer can do.

I am working on a DIY version of that system, so I will let you know how it turns out (at some point in the future).

Another project that uses carbon dosing without mandatory skimming is the Donovan's Nitrate destroyer, which is basically denitrification with carbon dosing inside a reactor. This system is run open loop with manual flow adjustments rather than being automated and ORP controlled like the DyMiCo filter. Another difference is that it is only for reducing nutrients rather than also replacing the CalRx functions like a DyMiCo does.

Dennis

 

[Randy Holmes-Farley]

Actually a somewhat well know method uses this exact format. The DyMiCo filter that is being sold in Europe uses carbon dosing and no skimmer. Their reasoning is that the skimmer removes too much of the zooplankton and allowing a robust food web to develop benefits the higher form inhabitants more than what the skimmer can do.

I am working on a DIY version of that system, so I will let you know how it turns out (at some point in the future).

Another project that uses carbon dosing without mandatory skimming is the Donovan's Nitrate destroyer, which is basically denitrification with carbon dosing inside a reactor. This system is run open loop with manual flow adjustments rather than being automated and ORP controlled like the DyMiCo filter. Another difference is that it is only for reducing nutrients rather than also replacing the CalRx functions like a DyMiCo does.

Dennis

I think what you are describing is a carbon denitrator, not organic carbon dosing to the aquarium. In such a method, the bacteria are grown in a reactor and usually under hypoxic conditions:

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

from it:

6. Carbon Denitrators

There are a variety of different commercial systems available, none of which are especially popular in the United States at this time. However, they can do a good job of removing nitrate and some aquarists like them.

In one of these types of systems, a carbon source is added to a portion of tank water in a low oxygen environment. In many cases, the carbon source is methanol. The methanol is mixed with aquarium water in a controlled situation (such as fluid pumped through a coil) and the methanol is consumed by bacteria that use nitrate as an electron acceptor instead of oxygen:

12 NO3– + 10 CH3OH + 12 H+ → 10 CO2 + 6 N2 + 26 H2O

The end result is that nitrate is removed from the aquarium. The typical drawback to such a system is the need for careful control over the conditions, and the consequent complexity that often accompanies such a reactor. Note again that this process returns the alkalinity (by consuming H+) that was lost in the production of the nitrate originally.

This method is similar to organic carbon dosing, but is localized inside of a reactor. Such localization can have advantages (less chance for cyanobacteria to be driven to grow more by consuming the organic), but it is a bit harder to accomplish technically than simple dosing of organics to the aquarium (described below).

 

[Dennis Cartier]

I think what you are describing is a carbon denitrator, not organic carbon dosing to the aquarium. In such a method, the bacteria are grown in a reactor and usually under hypoxic conditions:

This method is similar to organic carbon dosing, but is localized inside of a reactor. Such localization can have advantages (less chance for cyanobacteria to be driven to grow more by consuming the organic), but it is a bit harder to accomplish technically than simple dosing of organics to the aquarium (described below).

Yes, both methods are similar to the denitrators of old (like the Naturereef), but where they differ is the intent that the bacteria form the basis of he food chain. At least that is the premise that is put forth by DyMiCo and also suggested by Donvan. So in that regard the carbon dosing is also intending to be part of the food chain rather than purely an export mechanism. Frankly I can't wait to see if this is a viable way of feeding a bunch of hungry (and hopefully growing) corals.

Dennis