Can carbon dosing hurt fish?

[jasonrusso]

The basic principal of carbon dosing is the same regardless of the method (NOPOX, AZ-NO3, vodka, vinegar, sugar, etc), you are feeding bacteria that consumes NO3.

I've been dosing NOPOX for years, with subpar results so after a lot of research, I was thinking of trying AZ-NO3. I'll discontinue NOPOX when I make the switch.

I guess the greatest concern with carbon dosing, is oxygen deprivation. So as long as I have a few air pumps and my skimmer going I shouldn't have any concern aside from the product not working.

Is this correct? Obviously I would be using the recommended dose.

 

[jasonrusso]

BTW, this is a fish only tank, so rapidly dropping nutrient levels are not of a concern.

 

[shred5]

Sure it can be a risk.. You cause a large enough bacteria bloom it could deplete the oxygen levels, so don't do that!!

If you are careful it should really not be much risk at all...

 

[AllSignsPointToFish]

Make sure you have a really good oxygenation source or an oversized skimmer to keep dissolved oxygen up.

I'm sure you could also make the fish tipsy with too much vodka :p

 

[AllSignsPointToFish]

BTW, I'm surprised you haven't seen good results with NoPox. What are your nitrate levels now? What were they before? How big is the system and how much do you dose?

Sorry for all the questions. I'd like to help if I can.

 

[jasonrusso]

BTW, I'm surprised you haven't seen good results with NoPox. What are your nitrate levels now? What were they before? How big is the system and how much do you dose?

Sorry for all the questions. I'd like to help if I can.

210 gallon tank, nitrates 100. Have always been in the 80-100 range.

I have a reef octopus diablo XS 200 skimmer. Recently I've been dosing 30ml a day.

 

[AllSignsPointToFish]

Do you have a crushed coral gravel or other substrate that can trap detritus?

Is there an expiration data on the bottle of NoPox or has the lid been left open?

 

[jasonrusso]

BTW, I'm surprised you haven't seen good results with NoPox. What are your nitrate levels now? What were they before? How big is the system and how much do you dose?

Sorry for all the questions. I'd like to help if I can.

I want to try something different. AZ-N03 gets really good reviews on Marine Depot. Lots of people that say NOPOX didn't work for them as well, but this did.

It very well may just be carbon (reportedly it isn't), but if the only harm is to my wallet (my fish's health is the most important).

 

[AllSignsPointToFish]

Well, vodka is cheap and very effective at removing nitrates. It's also safe for fish in that kind of dosage.

I dose around 20 mL today of my homemade mixture of vodka and vinegar in a 125 gallon system. That should give you a reference point.

 

[jasonrusso]

This is also a step towards the solution, not the end solution. I have a large sulfur reactor that I am planning on setting up this weekend. That will take time to culture, and I would like to be starting with a lower number.

 

[jasonrusso]

Do you have a crushed coral gravel or other substrate that can trap detritus?

Is there an expiration data on the bottle of NoPox or has the lid been left open?

I have sand in the tank. I'm not sure about the exp date

 

[AllSignsPointToFish]

This is also a step towards the solution, not the end solution. I have a large sulfur reactor that I am planning on setting up this weekend. That will take time to culture, and I would like to be starting with a lower number.

I agree it's a step toward the solution (especially given the cost and dosing volumes). I looked at the product literature, and it appears that the AZ-NO3 product is actually enzymatic, not just encouraging the growth of the right types of bacteria.

I'm surprised that your nitrates remain that high. I assume you don't overfeed and do regular water changes. Have you ever checked the water you use as makeup? Maybe your water has a really high nitrate content to start?

 

[jasonrusso]

I agree it's a step toward the solution (especially given the cost and dosing volumes). I looked at the product literature, and it appears that the AZ-NO3 product is actually enzymatic, not just encouraging the growth of the right types of bacteria.

I'm surprised that your nitrates remain that high. I assume you don't overfeed and do regular water changes. Have you ever checked the water you use as makeup? Maybe your water has a really high nitrate content to start?

RODI tests zero. I change 15 gallons a week. My fish are just very messy eaters. I have an eel and s puffer which are the main "problems." I also have a lionfish, but he is relatively clean.

 

[AllSignsPointToFish]

Messy shouldn't matter. Whatever food enters the tank is eventually converted to nitrates and phosphates whether bacteria, fish, or cleanup crew do the dirty work. :)

I guess I should back up a step...are the nitrates causing you a nuisance algae issue or do you just not like them that high?

 

[rkpetersen]

I was thinking of trying AZ-NO3.

The writeup for this product is unscientific nonsensical gibberish. Sounds like a bunch of slight of hand, trying to pass carbon dosing off as something else.

 

[AllSignsPointToFish]

The writeup for this product is unscientific nonsensical gibberish. Sounds like a bunch of slight of hand, trying to pass carbon dosing off as something else.

LOL. I thought the same thing when I read it, but I didn't want to seem confrontational or inflammatory :)

I could probably have a GC-MS run on it to determine what's in it :)

 

[jasonrusso]

Messy shouldn't matter. Whatever food enters the tank is eventually converted to nitrates and phosphates whether bacteria, fish, or cleanup crew do the dirty work. :)

I guess I should back up a step...are the nitrates causing you a nuisance algae issue or do you just not like them that high?

I've had fish for years that are seemingly healthy, suddenly die (not parasite related).

I have 2 tanks, a small reef that has nitrates about 25ppm, and the big fish tank 100+. The fish seem much more active in the small tank.

I've always been told that nitrates didn't matter, but now I am obviously reconsidering that. 100ppm may not be acutely fatal, but i don't think it is good!

In my mind there are 3 types of fish, dead, surviving, and thriving. Just because the fish is alive, does not mean it is thriving.

 

[jasonrusso]

LOL. I thought the same thing when I read it, but I didn't want to seem confrontational or inflammatory :)

I could probably have a GC-MS run on it to determine what's in it :)

So if it is just carbon, it should work then.

 

[Dan_P]

The basic principal of carbon dosing is the same regardless of the method (NOPOX, AZ-NO3, vodka, vinegar, sugar, etc), you are feeding bacteria that consumes NO3.

I've been dosing NOPOX for years, with subpar results so after a lot of research, I was thinking of trying AZ-NO3. I'll discontinue NOPOX when I make the switch.

I guess the greatest concern with carbon dosing, is oxygen deprivation. So as long as I have a few air pumps and my skimmer going I shouldn't have any concern aside from the product not working.

Is this correct? Obviously I would be using the recommended dose.

I believe oxygen deprivation is a theoretical possibilty, but the dose of carbon being used and the rate of consumption of it by bacteria takes hours, making the likelihood low. Risk is equal to level of harm X likelihood of it happening. Don’t lose sleep over it. I doubt anyone has ever suffocated their fish while carbon dosing.

Your subpar results with carbon dosing might indicate that your system is generating more nitrates than can be removed by the bacteria at the dose being used. Is it possible that your bacteria are phosphate starved?

 

[JVU]

Carbon dosing only works if you have both excess nitrate and phosphate, with lack of a carbon source limiting the bacterial growth (Redfield ratio). So knowing your phosphate level is as important as knowing your nitrate level. If you eliminate phosphate with GFO or the like, carbon dosing won’t work well.

Also it requires an effective/overpowered skimmer, and works better when run relatively wet. If you don’t export the bacteria created they just degrade back into C/N/P.

I wouldn’t be worried about the O2 level with carbon dosing as long as you have good gas exchange and follow the directions.