Looking for thoughts on organic carbon dosing and nitrate

[Randy Holmes-Farley]

It is frequently claimed that it takes a long time (sometimes weeks) for organic carbon dosing to reduce nitrate.

Do folks believe that is true, and if it is, why would it be true?

Are most folks just starting to dose too slowly?

Bacterial number increase is sometimes cited as a reason, but why would it take that long?

If bacterial numbers increase is the reason, then where is the organic carbon going in the meantime? Accumulating? Being used somehow in a way that does not consume nitrate? What way is that?

Any thoughts are appreciated.

 

[sixty_reefer]

I thought if someone was to know the answer to that, it would of been you

 

[Bucs20fan]

I think the reason is people do not completely understand how efficient bacteria actually are. They can multiply incredibly fast in relation to nutrient available. Anyone whos ever had an infection can see just how fast it goes from bad to worse, sometimes in just hours.

Long story short, I think people say it takes so long because its a misconception that bacteria take a long time to increase their population in relation to the carbon being added.

 

[ReefHunter006]

I recently started back up carbon dosing and bio pellets. Starting both slow, thinking that once the carbon dosing starts to level the nutrients, that I can stop and the bio pellets will take it from there.

probably won’t work.

Either way, I assume there is residual carbon left over because my ph is suppressed compared to when I don’t use it. Is the residual ethanol or CO2, does the form of it matter, does seawater just convert it all to carbonic acid? Not sure, not a chemist. I also wonder if it hurts the bio-diversity by favoring a species.

I have had times where it works within two weeks and times where it works in 8. I don’t know why though.

 

[Spare time]

Could some other organisms be consuming the carbon source initially and in large quantities which could prevent an easy "take-off" of the bacteria which is desired for carbon dosing and protein skimming?

 

[Crustaceon]

I think organic carbon dosing can reduce nitrates incredibly quickly so long as there is sufficient P04 available and enough of a bacterial bloom is triggered. I believe in most cases, reefers are deathly afraid of seeing any degree of clouded water and simply don't add enough organic carbon to effectively offset nitrate production. IME, you can pretty easily decrease nitrates in a system by 10ppm per week BUT the display will be extremely cloudy and the skimmer cup will have to be emptied multiple times per day (don't smell it!). I say testing P04 during this process is an absolute must as I typically had to adjust for a daily .05ppm reduction in level. Yes, that much DAILY. Once phosphates would drop to around .02ppm, the nitrate reduction would stall completely, so you really have to stay on top of your P04 levels to get those huge results. For long-term maintenance, I'd probably dose enough organic carbon to generate a bacterial bloom within a day and then reduce the dosage just to the point where the consistent bloom is barely noticeable and only lasts for a few hours each day.

 

[MoshJosh]

could someone explain to me the carbon dosing process. I mean I sort of get it. . . but don't

Also aren't we adding carbon in some amount when we feed?

 

[Crustaceon]

could someone explain to me the carbon dosing process. I mean I sort of get it. . . but don't

Also aren't we adding carbon in some amount when we feed?

We technically are adding an organic carbon source simply by feeding because there are sugars etc. in the food. The difference is when we "carbon dose", that's an extremely concentrated amount of readily available organic carbon for bacteria to consume. In turn, the bacterial will also consume some nitrates and phosphates. At this point, a protein skimmer is able to capture and export that gut-loaded bacteria out of the system. Something like vinegar is a really good food for bacteria right off the bat, whereas if you just fed the tank, that bacteria would have to wait for that food to decompose a little bit before it could access the carbon in that food the same way as it did with the vinegar.

 

[MoshJosh]

We technically are adding an organic carbon source simply by feeding because there are sugars etc. in the food. The difference is when we "carbon dose", that's an extremely concentrated amount of readily available organic carbon for bacteria to consume. In turn, the bacterial will also consume some nitrates and phosphates. At this point, a protein skimmer is able to capture and export that gut-loaded bacteria out of the system. Something like vinegar is a really good food for bacteria right off the bat, whereas if you just fed the tank, that bacteria would have to wait for that food to decompose a little bit before it could access the carbon in that food the same way as it did with the vinegar.

Thank you! So this does not work without a skimmer. Also, does the low pH of the vinegar effect the overall pH?

 

[Boogieman]

I think I am an anomaly to this .. I have been dosing vodka for a few months now i am up to 15 ml per day Also have biopellets.in a fluidized reactor
. Protien Skimmer is not over active at all. I see no reduction in Nitrates or Phosphate . I used to increase 1 ml per week and have recently started increasing 2 ml per week.. tonight when I get home and test I suspect I will need to go up again.

 

[Crustaceon]

Thank you! So this does not work without a skimmer. Also, does the low pH of the vinegar effect the overall pH?

Yeah, a skimmer is necessary item for this. I can't really think of a different way to get the same functionality. As for ph, you're only adding let's say 40ml to 100g of tank water. The impact it has on overall ph is negligible. I'd say a calcium reactor has a greater impact than carbon dosing. If you dose vodka (another even more concentrated carbon source) you won't have any noticeable decrease in ph.

 

[Crustaceon]

I think I am an anomaly to this .. I have been dosing vodka for a few months now i am up to 15 ml per day Also have biopellets.in a fluidized reactor
. Protien Skimmer is not over active at all. I see no reduction in Nitrates or Phosphate . I used to increase 1 ml per week and have recently started increasing 2 ml per week.. tonight when I get home and test I suspect I will need to go up again.

For reference, my daily dose in my 200g total system was 40ml of diy nopox and that was for a light clouding. When I say this, I mean if you look through one side panel, you can just barely see the other panel. A major point here is having at least .08ppm phosphates. You don't want to peg P04 at zero even momentarily or it'll stall nutrient reduction. And for some reason my skimmer would only really go berserk after the lights went out. I'm guessing it would have something to do with the night time ph shift. Maybe one of our resident researchers can investigate that.

 

[Boogieman]

For reference, my daily dose in my 200g total system was 40ml of diy nopox and that was for a light clouding. When I say this, I mean if you look through one side panel, you can just barely see the other panel. A major point here is having at least .08ppm phosphates. You don't want to peg P04 at zero even momentarily or it'll stall nutrient reduction. And for some reason my skimmer would only really go berserk after the lights went out. I'm guessing it would have something to do with the night time ph shift. Maybe one of our resident researchers can investigate that.

 

[Boogieman]

For reference, my daily dose in my 200g total system was 40ml of diy nopox and that was for a light clouding. When I say this, I mean if you look through one side panel, you can just barely see the other panel. A major point here is having at least .08ppm phosphates. You don't want to peg P04 at zero even momentarily or it'll stall nutrient reduction. And for some reason my skimmer would only really go berserk after the lights went out. I'm guessing it would have something to do with the night time ph shift. Maybe one of our resident researchers can investigate that.

 

[Boogieman]

Thank you for that. I could not find refference for that high of a dose. I have a 120 gallon so looks like I have a bit more room to move . Always felt like I was way too high.

 

[Joe31415]

I thought if someone was to know the answer to that, it would of been you

It's like the mechanic asking why *you* think your car won't start.

 

[Borat]

I think the reason is people do not completely understand how efficient bacteria actually are. They can multiply incredibly fast in relation to nutrient available. Anyone whos ever had an infection can see just how fast it goes from bad to worse, sometimes in just hours.

Long story short, I think people say it takes so long because its a misconception that bacteria take a long time to increase their population in relation to the carbon being added.

It's not always the case - nitrobacter is actually a very slow growing bacteria (think about how long it takes for a new tank to start showing signs of Nitrates reduction), probably because their energy source is so poor..

 

[Borat]

I have no protein skimmer, I do no carbon dosing and - unfortunately I also have no detectable nitrates...

 

[Troylee]

The fish drink the excess duh! Hahaha.. I’d guess it’s skimmed out but you’d know more than us.. I kinda feel like this is a test hmmmmm..

 

[Crustaceon]

Thank you for that. I could not find refference for that high of a dose. I have a 120 gallon so looks like I have a bit more room to move . Always felt like I was way too high.

Back when I had a 100g + 20g sump, I dosed around 30ml of vodka daily to get nitrates in check over the course of a few months. I ended up with an 8ml daily maintenance dose after that.