Carbon dosing without a skimmer

[CoralClasher]

The GFO lowered the P

Yeah I’m sure it was the GFO. The water does look a little cleaner today maybe the vinegar helps maybe not but no bad effects yet from the vinegar.

 

[CoralClasher]

Do I want to keep lowering the phosphate if the No3 isn’t moving? I don’t want to end up with a big imbalance between the two do I?

 

[Dkeller_nc]

There's been a good deal of debate about the Redfield Ratio, which purports to suggest that the molar ratio of the elements carbon, nitrogen and phosphorus in living creatures in the world's oceans is a constant of 106:16:1. I don't mean to start a debate about the accuracy of those numbers - there's endless discussion of whether the actual numbers really apply to the rather strong difference between heterotrophic bacteria and phytoplankton.

However, there's something to be said about interpreting the RR as the amount of phosphorus required for the growth of microorganisms is sharply lower than the amount of carbon and nitrogen. Without actually doing the calculations this morning, though, I'd say that 0.46 ppm of phosphate should be well above the level that it would limit the growth of bacteria in your system. Instead, I would think that the limiting element is probably carbon in the form of easily accessible organic acids/sugars (i.e., in your case, vinegar).

I would suggest SLOWLY increasing the daily dose of vinegar to perhaps 8 mL per dose, and hold it there for a couple of weeks. As you may already be aware, the danger with carbon dosing, whether it be in the form of vinegar, sugar or ethanol, is adding too much and causing a bacterial bloom that sucks all of the oxygen out of the water and kills your inhabitants. That danger would be particularly acute on a tank without a skimmer that depends on diffusion of oxygen through the limited top surface level of the tank.

 

[CoralClasher]

There's been a good deal of debate about the Redfield Ratio, which purports to suggest that the molar ratio of the elements carbon, nitrogen and phosphorus in living creatures in the world's oceans is a constant of 106:16:1. I don't mean to start a debate about the accuracy of those numbers - there's endless discussion of whether the actual numbers really apply to the rather strong difference between heterotrophic bacteria and phytoplankton.

However, there's something to be said about interpreting the RR as the amount of phosphorus required for the growth of microorganisms is sharply lower than the amount of carbon and nitrogen. Without actually doing the calculations this morning, though, I'd say that 0.46 ppm of phosphate should be well above the level that it would limit the growth of bacteria in your system. Instead, I would think that the limiting element is probably carbon in the form of easily accessible organic acids/sugars (i.e., in your case, vinegar).

I would suggest SLOWLY increasing the daily dose of vinegar to perhaps 8 mL per dose, and hold it there for a couple of weeks. As you may already be aware, the danger with carbon dosing, whether it be in the form of vinegar, sugar or ethanol, is adding too much and causing a bacterial bloom that sucks all of the oxygen out of the water and kills your inhabitants. That danger would be particularly acute on a tank without a skimmer that depends on diffusion of oxygen through the limited top surface level of the tank.

Thanks for the reply. I do know the danger of bacteria blooms. I’m running an Oxadator and a wooden air stone from outside air with good surface movement. I’m a big fan of the bacteria method from elegant corals for Dino that uses vodka. This is my first time using vinegar and I don’t want to cause a cloudy water bloom but would like to know how much vinegar is too much?

 

[Alenya]

If it’s any help my tank is a 55 gal 2 months old with 8 fish. I also started with dino and had to dose phosphate to get algae going instead. My nitrates are high due to feeding 3x a day. It was 80 and is currently 40. I run a Clarisea and a skimmer. I just added 2kg of bioballs to the sump and am dosing 5ml of vinegar daily (just started). I am still dosing phosphate as well.

I don’t think you can do this safely without a skimmer with so many fish; at the very least a bubbler would be a precaution or run a skimmer without the cup for aeration?

 

[Dkeller_nc]

That's tough to say. Randy Holmes Farley published this chart a few years ago that would suggest that the ultimate dose would be around 70mL after 16 weeks. Personally, and perhaps Randy will comment, but I regard this chart as a maximum, not-to-be-exceeded dosing guide. I generally don't approach the amounts in the table, and tend to use perhaps 1/10th the maximum listed for the tank size after 16 weeks.

I do that for a couple of reasons. The first is that the only danger in underdosing is that you don't get the desired effect, but in general nitrate isn't toxic to marine critters unless you're talking about a really excessive concentration of 100ppm or more. Since overdosing will have a very bad effect indeed, I stay on the cautious side. The second reason is that in my tanks, dosing is only required to get the bacterial action jump-started, so I generally only add vinegar for 3 or 4 weeks at most. After that period of time, my tanks don't accumulate nitrate. In fact, I just tested 4 of my tanks this morning and got back 0ppm to 0.5ppm via the Salifert test.

However, all tanks are different, and I recognize that my experience may not be typical, perhaps as a result of using actual live rock from the ocean and a 2" sand bed. Others have had different results where they need to continuously dose a carbon source for months. One thing to keep in mind is that vinegar is very, very dilute as a carbon source compared to 80 proof vodka. That's one reason I recommend vinegar over vodka to folks that are new to carbon dosing, as it's pretty difficult to accidentally overdose vinegar, whereas in the case of vodka it can be quite easy to do so with disastrous results.

 

[Nano sapiens]

FWIW, I'm at the end ramp down stages of carbon dosing (vinegar, no skimmer or other aeration), having brought NO3 down from ~24 to 4 ppm in a little less than 2 months. Basically, after much reading on the topic, I decided on a conservative dosing of 0.5 ppm vinegar/10g of water volume/day (ramp up for the 1st week was simply half this amount) and this proved sufficient to gradually bring NO3 down in my system to my target range of 2-4 pp). To help remove the bacteria from the system, I used my normal maintenance consisting of a 10% weekly water change plus a gravel vac and a filter sock temporarily attached to my pump's outlet tube on water change day (biofilm and detritus removal).

I didn't notice any coral issues day or night (as expected). What I did notice is that instead of having my typical very thin brown/green algae layer on my glass after 3-4 days, it was replaced by a similarly thin layer of white biofilm (especially noticeable in the last two weeks). The amount of nuisance algae in general has declined somewhat, possibly due to reduced PO4 levels (always have been undetectable in this system of 12+ years). Water clarity has been exceptional. I've been very careful to keep the feeding of the system very consistent (same foods on the same days at the same amounts) during this period to see if the dosing was making the difference as opposed to any changed variable(s) in the system.

For the next week I'll be cutting the vinegar dosage in half and will check at the end of the week if NO3 is holding steady. Assuming no rise, I will stop dosing the following week and monitor NO3 weekly for a few weeks to see if the NO3 level stays stable, or not.

Naturally, every system will be different and possibly require more carbon to achieve similar NO3 reduction. But I hope that a first-hand account proves useful.

 

[CoralClasher]

FWIW, I'm at the end ramp down stages of carbon dosing (vinegar, no skimmer or other aeration), having brought NO3 down from ~24 to 4 ppm in a little less than 2 months. Basically, after much reading on the topic, I decided on a conservative dosing of 0.5 ppm vinegar/10g of water volume/day (ramp up for the 1st week was simply half this amount) and this proved sufficient to gradually bring NO3 down in my system to my target range of 2-4 pp). To help remove the bacteria from the system, I used my normal maintenance consisting of a 10% weekly water change plus a gravel vac and a filter sock temporarily attached to my pump's outlet tube on water change day (biofilm and detritus removal).

I didn't notice any coral issues day or night (as expected). What I did notice is that instead of having my typical very thin brown/green algae layer on my glass after 3-4 days, it was replaced by a similarly thin layer of white biofilm (especially noticeable in the last two weeks). The amount of nuisance algae in general has declined somewhat, possibly due to reduced PO4 levels (always have been undetectable in this system of 12+ years). Water clarity has been exceptional. I've been very careful to keep the feeding of the system very consistent (same foods on the same days at the same amounts) during this period to see if the dosing was making the difference as opposed to any changed variable(s) in the system.

For the next week I'll be cutting the vinegar dosage in half and will check at the end of the week if NO3 is holding steady. Assuming no rise, I will stop dosing the following week and monitor NO3 weekly for a few weeks to see if the NO3 level stays stable, or not.

Naturally, every system will be different and possibly require more carbon to achieve similar NO3 reduction. But I hope that a first-hand account proves useful.

Lots of good information thanks. One more question what time of the day do you dose vinegar?

 

[Nano sapiens]

Lots of good information thanks. One more question what time of the day do you dose vinegar?

I simply added the vinegar to my Kalkasser/RO ATO at a concentration that would provide 0.5 ml/day/10g and so dosed it that way.

 

[CoralClasher]

Little update, I’m up to 10ml a day of vinegar. I’m not getting the nutrients to drop but they are not going up. Things are looking good. Still getting green film on glass three days.
Would alternating carbon sources help anything?

 

[CoralClasher]

Is denatured alcohol ever used for carbon source?

 

[nereefpat]

Is denatured alcohol ever used for carbon source?

Do not use denatured alcohol. Denatured alcohol is alcohol mixed with other chemicals to make it poison.

 

[CoralClasher]

Do not use denatured alcohol. Denatured alcohol is alcohol mixed with other chemicals to make it poison.

Is there any other carbon sources around the house besides vinegar and vodka that are reef safe?

 

[nereefpat]

Is there any other carbon sources around the house besides vinegar and vodka that are reef safe?

Table Sugar

 

[CoralClasher]

Table Sugar

Any reported problems with using sugar? Is using multiple carbon sources good idea?

 

[nereefpat]

Any reported problems with using sugar? Is using multiple carbon sources good idea?

I haven't carbon dosed with sugar, so I'm probably the wrong guy to comment on that.

Some people report cyano with certain carbon sources, but I'm not sure if that makes sense to me.

 

[CoralClasher]

I haven't carbon dosed with sugar, so I'm probably the wrong guy to comment on that.

Some people report cyano with certain carbon sources, but I'm not sure if that makes sense to me.

I don’t want to jinx myself but I never had Cyano problem in this tank. My macro tank that I feed the fish has Cyano and I never use carbon in that tank.

 

[Randy Holmes-Farley Verified Community Expert]

Any reported problems with using sugar? Is using multiple carbon sources good idea?

My corals browned up on sugar, and folks report more problems generally with sugar than ethanol (vodka) or acetic acid(vinegar), but there was a recipe a while back using vinegar, vodka and sugar called VSV.