Dosing carbon, time of day ?

[oceanarium]

After testing today both systems are responding quite dramatically to the change in the timing of the carbon dose.

Both have significantly increased the need for more nitrogen additions at the same time require less carbon dose.

Pete

[Roy]

So less carbon more often but be prepared for increased nitrogen consumption.

[oceanarium]

No I was consuming more carbon whilst dosing hourly and consuming less N.

By changing to dosing every 12 hours I have reduced the amount of carbon dose and had to increase the amount of N additions.

Why I don't know could be more activity from the algae refugiums I have or something to do with how the algae and corals are competing better for N and P resources ?

Our aquariums are complex eccosystems, well beyong fully understanding exactly what is happening at best we can only use educated guesses. Its quite likely someone else with a diferent system will see a toally different response.

After maintenance day again I did see that misty look again the following day.... Perhaps I am lossing some nitrification from the carbon reactor media. I dont use much so would have thought the volume insignificant a cup full for 5000ltrs.

Pete

[Onsan]

If you don't measure residual organic carbon (TOC test), how do you know that you were consuming more carbon instead of simply dosing more?
Also, keep in mind that organic carbon's roll in biological systems is not mutually exclusive to denitrification.

[oceanarium]

If you don't measure residual organic carbon (TOC test), how do you know that you were consuming more carbon instead of simply dosing more?
Also, keep in mind that organic carbon's roll in biological systems is not mutually exclusive to denitrification.

Thanks for the correction.

About the best i can word it is, since moving to a twice per day dose;

I have needed to raise NO3 additions to try meet my target range of 0.500 plus.

Lower the carbon dose to meet my PO4 target of 0.03-4.

As to the mechanics of it I will be the first to admit I have no idea why or how, it makes no sense to me. So i should not be presuming the actual biological carbon consumption is less.

I am just happy to be seeing that crystal clear water and so far the bio clogging on the second system of the carbon media etc is looking very promising to be fixed.

Still fine tuning to get the balance right with the N and P ratios on the second system so not calling it fixed just yet. The low N washed out some of the corals and they will need a little time to recover.

[Onsan]

I don't doubt your results at all, just pointing out that if you don't measure something you can't reliably assume to know it's quantity, and something like organic carbon (ie: energy) is used in so many ways by so many organisms; bacteria, fungi, sponges, algae and I suspect corals (through their zoox, but can't state) and not all for the purpose of denitrification.
I don't mean to dissuade you, just to broaden the perspective from which you draw conclusions.

[oceanarium]

No worries i was not having a go at you

I agree totally, I really don't understand why the timing of the dose would effect how the nutrients are assimilated into or removed from the system.

Testing day again today, so will be interesting to see the trend.

[Onsan]

No worries i was not having a go at you

didn't think you were, more the opposite was my concern.

I like your work, it makes for good reading and critical thought; you're applying the scientific method (the systematic observation, measurement, and experiment, and the formulation, testing, and modification of hypotheses) and effectively you're publishing your work through MASA and using it as the peer review process.
Peer review is a huge part in developing a theory; you're employing other like minded folk to examine and apply some critical thinking to your findings. That feedback either gives you the support for the hypothesis to eventually become a theory or the information to review the hypothesis and reapply the method until you do get a hypothesis that can one day be considered a theory.

I like reading this stuff, wouldn't come here if not for this, everything else here lately is kinda banal.

[Matt1961]

Onsan, Ocenarium,
Great read and good solid debate love it

Just a thought on the reasons why from observations from my Carbon dosing experience

Do you think the increased N And Phos removal could be due to the bacteria experience a massive bloom due to large carbon dose and then dying off quickly once the food has been consumed, and then being removed by the skimmer more effectively due to their greater numbers? as apposed to a gradual build up of bacteria to a sustainable level with a continual dose through the day?

Where do you dose your carbon Oceanarium? directly before the skimmer? into the DT? I dose mine into the sump just prior to skimmer but thinking of moving it into the return section of my sump?

I had my carbon dosing line fall out and onto the floor, dosed carbon onto the floor for a couple of days before the smell of vinegar and vodka made me look at why
When I reconnected the dosing line I gave it an additional dose to make up for what it missed while the hose was out and the next day I had significantly more skimmate than normal and it was a lot smelly than normal as well?

FYI I'm dosing Vodka/vinegar mix

Matt

[oceanarium]

Tests came back great today Phos good N still needed a little tweeking upwards.

Cleaning the glass today no signs of algae/ diatoms at all, just the slightest hint of a bacteria biofilm. Cleanest it has been in a long time.

The second system had almost no clumping on the carbon medium last week. This week it was perfect, but that could be due to the reduced carbon dose as much as the changing of the timing.

Do you think the increased N And Phos removal could be due to the bacteria experience a massive bloom due to large carbon dose and then dying off quickly once the food has been consumed, and then being removed by the skimmer more effectively due to their greater numbers? as apposed to a gradual build up of bacteria to a sustainable level with a continual dose through the day?

It is one of the thoughts I had been pondering. I cant say I have noticed and changes in skimate, but that is not to say it is holding more bacteria wastes its just not observable.

I was reading this article, a bit to complex and lengthy for me to fully digest. Quote is from the last section 3.3 and refers to section 1.2 sub heading (Bacterial Surface Charge and Protein Skimming)

http://www.advancedaquarist.com/2011/3/aafeature

there appears to be two functionally distinct populations of bacteria; one that is susceptible to bubble-based removal, and one that is not.

Not sure how this may be able to apply to a larger carbon dose able to skew the population to be more susceptible bacteria to skimming?


I dose in the sump near the area of the skimmer, I don't think it would matter much. More important to direct discharge from a biopellet reactor to the skimmer, there is more likely hood of clumping bacteria to get directly expelled.