Another denitrification biological thread

[chicago]

Interesting observation on the article Randy... .. I believe I will try the simple approach first and start dosing the tank... right now i have not added a lot of sps back into my DT..

 

[cvicente]

I accept that there is a reasonable hypothesis that organic carbon dosing could cause coral issues in a reef tank, and accept that folks might reasonably choose to not do or do it remotely out of fear for causing growth of problematic bacteria (that was my fear when folks first started suggesting it years ago).

But that said, those data (at least in the above posted article) do not convince me. In that experiment, the corals were placed alone in an aquarium with sugars dosed (huge dose, no nutrient monitoring after organic dosing) . There is literally no other bacteria or surfaces for the bacteria to grow on except what comes in on the coral (at least they mention none). It seems a highly skewed experiment, but I agree that it shows the theoretical possibility.

That said, what is the real risk? Do people see RTN when dosing vinegar or vodka (not sugars) to a real reef tank? I've really not noticed much of a correlation between the incidence of organic carbon dosing and RTN (compared to not using organic carbon dosing and having RTN).

Both RTN and organic carbon dosing are reasonably common in reef tanks. Has anyone notice a substantial correlation that goes beyond what one would expect for two common things to occur together compared to apart?

I did experience the problem first hand with my aquarium, with vodka, vinegar and biopellets. When the dose reached the point where NO3 and PO4 were reduced STN started to show from the base up followed by RTN. I tried direct carbon dosing four times until I gave up. I explained this problem to Julian Sprung when he visited the Island in April 2016. He introduce me to the work of Dr. Rohwer. Although he knows the experiment was not oriented to the aquarium trade or under normal aquarium conditions he believed there could be a connection, "important ones" as he mentioned in his email, linking the work of Forest Rohwer and carbon dosing in aquariums. Anyways, you have always been a skeptic with the work of others. I invite you to run your own controlled experiment with all the methodology you understand are correct and enlighten us with your findings.

 

[Randy Holmes-Farley Verified Community Expert]

I did experience the problem first hand with my aquarium, with vodka, vinegar and biopellets. When the dose reached the point where NO3 and PO4 was reduced STN started to show from the base up followed by RTN. I tried direct carbon dosing four times until I gave up. I explained this problem to Julian Sprung when he visited the Island in April 2016. He introduce me to the work of Dr. Rohwer. Although he knows the experiment was not oriented to the aquarium trade or under normal aquarium conditions he believed there could be a connection, "important ones" as he mentioned in his email, linking the work of Forest Rohwer and carbon dosing in aquariums. Anyways, you have always been a skeptic with the work of others. I invite you to run your own controlled experiment with all the methodology you understand are correct and enlighten us with your findings.

Well, I did use direct organic carbon dosing for years, as have lots of others. I had my tank up for a decade or more without organic dosing, then switched to organic carbon dosing and observed it for more years. That seems like a good experiment, exactly replicating how a hobbyist (myself) would use it. Obviously my experiment did not have all the corals folks keep (it was not primarily SPS) and certainly I did not have every possibly pathogenic bacterial species in the tank waiting to take off.

I don't discount it may have happened in your case, and there may be a number of reasons why, and pathogenic bacteria on the coral is a possibility. So is nutrients too low, nutrients dropped too fast, coincidence, pH changes, O2 changes, too much dosing, excessively lowered trace elements, etc.

Quite a few people, including those with mostly SPS, do not have an issue with organic carbon dosing. Some have reported an issue. It certainly may be the case that there is a smallish subset of reefers who had corals die due to pathogenic bacteria growing on corals. But a fairly large number of people have corals die who are not dosing organic carbon. That makes it hard to see the underlying correlation clearly.

There are a variety of apparent advantages and disadvantages to direct dosing, and while I and most others did not detect coral death as an apparent consequence, I certainly cannot rule it out in all cases.

 

[chicago]

thanks for all the input guys..

 

[SteadyC]

I did experience the problem first hand with my aquarium, with vodka, vinegar and biopellets. When the dose reached the point where NO3 and PO4 were reduced STN started to show from the base up followed by RTN. I tried direct carbon dosing four times until I gave up. I explained this problem to Julian Sprung when he visited the Island in April 2016. He introduce me to the work of Dr. Rohwer. Although he knows the experiment was not oriented to the aquarium trade or under normal aquarium conditions he believed there could be a connection, "important ones" as he mentioned in his email, linking the work of Forest Rohwer and carbon dosing in aquariums. Anyways, you have always been a skeptic with the work of others. I invite you to run your own controlled experiment with all the methodology you understand are correct and enlighten us with your findings.

Dude, that was very rude. @Randy Holmes-Farley contributes to tons of topics, written many articles on advancedaquarists.com and other sites, helps reefers many times more than anyone else on reef2reef, he is entitled to his own opinion as you are yours. No reason to challenge him and call him a skeptic.

 

[vio]

Dude, that was very rude. @Randy Holmes-Farley contributes to tons of topics, written many articles on advancedaquarists.com and other sites, helps reefers many times more than anyone else on reef2reef, he is entitled to his own opinion as you are yours. No reason to challenge him and call him a skeptic.

+1
Some ppl. grow Corals , some try to grow.......Rocks.

 

[chicago]

Yep Randy has given some great info over the years.

 

[neilenet]

ok. So I have large system. 600 gallon plus. In the past used DSB in my 300 gallon sump to control nitrate. I trashed it and got 14 Marine pure bio blocks and along wit hmy live rocks to control nitrate. Well the blocks been in low flow are not denting the nitrate. I was planning on perhaps putting the blocks in a container so only tops of them get flow..

Another thought is to install a large 6 inch round by 4 foot tube full of bio media. And allow tank wAter to pass through. The end of the tube would lack oxygen for nitrate conversion to gas with possible feed for some vodka or vinegar Addition to feed bacteria.

Other thought. Is to take some of the blocks and use that media in the reactor. Fabricate some type of square media reactor to house let's say five of these blocks and feed it.

Thoughts. Please. Question also. If the blocks in the sump are only creating nitrate. A nitrate factor like in the days of bio balls in a drip plate, The will anyreactor be able to handle the nitrate. ...?

I built a box like this in the early 90's. It worked great as long as I had the tank. On a 120 gallon tank. With only a wet dry filter and protein skimmer. Hardly ever did water changes.