Nitrate removal without phosphates.

[Heres_doe_]

I want to know something that I read somewhere a while ago. If you're carbon dosing, you cannot remove nitrates with little or no phosphates present. Is this correct? I have noticed when my phosphates bottom out my nitrates will continue rising. If I have phosphates they will go down.

 

[Randy Holmes-Farley Verified Community Expert]

I want to know something that I read somewhere a while ago. If you're carbon dosing, you cannot remove nitrates with little or no phosphates present. Is this correct? I have noticed when my phosphates bottom out my nitrates will continue rising. If I have phosphates they will go down.

It is not strictly correct as written, no. Denitrification as a process consumes nitrate and does not consume phosphate.

It is true, however, that growth of organisms, from bacteria to corals, may go faster when all of organic carbon, a source of N, and a souce of P are all present in sufficient quantity.

 

[Heres_doe_]

So carbon dosing will still remove nitrates without phosphates present?

 

[Randy Holmes-Farley Verified Community Expert]

So carbon dosing will still remove nitrates without phosphates present?

It can. Whether it does in any given tank is a different question. It depends on whether there is an appropriate environment (like sand of sufficient depth, etc.), and how fast the organic might get used up before penetrating that low O2 environment.

 

[Salty_Northerner]

Can I ask what is carbon dosing?

I have a bag of seachem carbon in my media basket, it that the same thing?

 

[Randy Holmes-Farley Verified Community Expert]

Can I ask what is carbon dosing?

I have a bag of seachem carbon in my media basket, it that the same thing?

No.

That is granular activated carbon, or GAC. It is for exporting organics like proteins that bind to it, keeping the water less yellow, etc.

Organic carbon dosing is adding a small molecule organic material, like ethanol in vodka, that organisms such as bacteria consume, lowering nutrients and having other effects.

 

[Salty_Northerner]

No.

That is granular activated carbon, or GAC. It is for exporting organics like proteins that bind to it, keeping the water less yellow, etc.

Organic carbon dosing is adding a small molecule organic material, like ethanol in vodka, that organisms such as bacteria consume, lowering nutrients and having other effects.

So if my nitrates are high, then pour a little vodka in the water?

I tested my parameters yesterday.
Salinity 1.025
Temp 78.1
pH 8.07
Ca 422
dkH 8.2
Mag 1400
Phosphorus 7ppb/ 0.021 phosphate
Nitrate 12.4

Since ditching seachem fusion 1 & 2 and now using B-ionic 2 part the calcium and dkH has stabilized.

Should I bother doing a water change? WWC was saying their nitrates are around 10-15 so what's your thoughts?

 

[Randy Holmes-Farley Verified Community Expert]

So if my nitrates are high, then pour a little vodka in the water?

I tested my parameters yesterday.
Salinity 1.025
Temp 78.1
pH 8.07
Ca 422
dkH 8.2
Mag 1400
Phosphorus 7ppb/ 0.021 phosphate
Nitrate 12.4

Since ditching seachem fusion 1 & 2 and now using B-ionic 2 part the calcium and dkH has stabilized.

Should I bother doing a water change? WWC was saying their nitrates are around 10-15 so what's your thoughts?

Those values are all fine, except maybe phosphate is a tad low. I generally recommend 2-10 ppm nitrate, with above that range better than below it.

Here's a vodka dosing article:

https://reefkeeping.com/issues/2008-08/nftt/index.php#:~:text=The%20starting%20dosage%20is%200.1,twice%20daily%20for%20more%20consistency.

and one for vinegar:

Reefkeeping Magazine - Vinegar Dosing Methodology for the Marine Aquarium

Reefkeeping ...an online magazine for the marine aquarist.

reefkeeping.com