Adding Nitrates to Naturally Raise Alkalinity

[GARRIGA]

Randy,

Since denitrification (for example) raises alkalinity by returning base then would adding additional nitrates allowed to be processed by denitrification or plants then add additional alkalinity in a no water change system?

 

[Randy Holmes-Farley Verified Community Expert]

Randy,

Since denitrification (for example) raises alkalinity by returning base then would adding additional nitrates allowed to be processed by denitrification or plants then add additional alkalinity in a no water change system?

I might quibble how natural it is (vs just adding baking soda), but yes, dosing nitrate that gets consumed will boost alk.

Note that there is no ion accumulation difference between dosing sodium bicarbonate and sodium nitrate to boost alk. Both end up accumulation ions such as sodium and whatever counter ion is being added with the calcium (like chloride) that is being used to take that alkalinity into calcium carbonate.

 

[GARRIGA]

I might quibble how natural it is (vs just adding baking soda), but yes, dosing nitrate that gets consumed will boost alk.

Note that there is no ion accumulation difference between dosing sodium bicarbonate and sodium nitrate to boost alk. Both end up accumulation ions such as sodium and whatever counter ion is being added with the calcium (like chloride) that is being used to take that alkalinity into calcium carbonate.

Mentioned nitrates to isolate the question but my approach would be to over feed and having an oversize refugium handle the conversion. Avoiding sodium or chloride my main concern. AFR, calcium reactor and or Kalk the current thought process to provide the necessary major elements.

 

[Randy Holmes-Farley Verified Community Expert]

Mentioned nitrates to isolate the question but my approach would be to over feed and having an oversize refugium handle the conversion. Avoiding sodium or chloride my main concern. AFR, calcium reactor and or Kalk the current thought process to provide the necessary major elements.

Calcium hydroxide avoids the sodium and chloride accumulation and adds alk and calcium.

Calcium nitrate would behave the same way, but with a lower pH effect.

 

[GARRIGA]

Calcium hydroxide avoids the sodium and chloride accumulation and adds alk and calcium.

Calcium nitrate would behave the same way, but with a lower pH effect.

Wasn't aware of calcium nitrate as an option. Thanks. Chemistry not my wheel house and why I come here for answers.

Kalk will be used to help with pH but my room is so high in co2 that based on prior use it raises alkalinity well beyond practical use with little affect to pH although I'm wondering if employing an oversized Fuge and sealing the surface from room interaction will either elevate pH enough or allow Kalk to be more efficient at raising pH since macroalgae can pull from suspension the co2 without my system having to equalize with my room air. Filtration will be a closed loop system therefore evaporation will be at a minimum which also reduces the effectiveness of Kalk unless I dose a slurry which I'm still learning about. All points I plan on testing before final design.

Are there are other forms of nitrate not adding calcium or sodium? Current test tank has no calcium consuming organism and purely setup for decomposition and pH testing. Other than overfeeding I have no other conceivable options

 

[Randy Holmes-Farley Verified Community Expert]

Wasn't aware of calcium nitrate as an option. Thanks. Chemistry not my wheel house and why I come here for answers.

Kalk will be used to help with pH but my room is so high in co2 that based on prior use it raises alkalinity well beyond practical use with little affect to pH although I'm wondering if employing an oversized Fuge and sealing the surface from room interaction will either elevate pH enough or allow Kalk to be more efficient at raising pH since macroalgae can pull from suspension the co2 without my system having to equalize with my room air. Filtration will be a closed loop system therefore evaporation will be at a minimum which also reduces the effectiveness of Kalk unless I dose a slurry which I'm still learning about. All points I plan on testing before final design.

Are there are other forms of nitrate not adding calcium or sodium? Current test tank has no calcium consuming organism and purely setup for decomposition and pH testing. Other than overfeeding I have no other conceivable options

Calcium and sodium nitrate are the best options. You can buy many chemicals as nitrate salts, but there's no advantage to any of them.

Overfeeding will not boost alkalinity. The conversion of the food to nitrate depletes alk, and the consumption of all the nitrate will add back the alk lost, resulting in a net zero change to alk.

 

[GARRIGA]

Overfeeding will not boost alkalinity. The conversion of the food to nitrate depletes alk, and the consumption of all the nitrate will add back the alk lost, resulting in a net zero change to alk.

That makes sense and completely forgot that part.

Calcium nitrate then the best option. Found a post you interacted on with calcium nitrate. Going to study it and see how to best implement it. Not concerned with the additional ammonia possibly included. I'm a fan of ammonium.

 

[Randy Holmes-Farley Verified Community Expert]

That makes sense and completely forgot that part.

Calcium nitrate then the best option. Found a post you interacted on with calcium nitrate. Going to study it and see how to best implement it. Not concerned with the additional ammonia possibly included. I'm a fan of ammonium.

Sounds good.

Good luck!