Optimal carbon dose timing

[Faulkner’s maze]

Hello -
My question is this-currently I am trying to optimize carbon dose timing -

Right now I am dosing 1.6 ml of bacto balance and I feed 9:00, 12:00, 14:00, 16:00 a combo of pellets (morning) and then ROE and artic pods afternoon (automated)

I essentially have it so that doses are broken down nearly even 30 min and 45 min after feeding.

As I will need to decommission the mini fridge (leaking and internal temp controller not stable) that has pods/ROE I will be reverting to feeding pellets 2-3x a day instead.. with some other coral food later in the evening (don’t intend to dose after lights out).

I keep the skimmer going now at feeding.
Are there optimal time periods before /after feeding to dose and should I start with a dose right after lights on -8:00 am

Thank you for any input.

 

[Randy Holmes-Farley]

Why do you want to carbon dose? Are nutrients too high? How high?

I generally recommend carbon dosing during the day when pH and O2 are highest, because it tends to lower both pH and O2 after it is dosed.

I really do not think trying to time organic carbon dosing against foods added to the tank is a worthwhile consideration.

 

[Faulkner’s maze]

Why do you want to carbon dose? Are nutrients too high? How high?

I generally recommend carbon dosing during the day when pH and O2 are highest, because it tends to lower both pH and O2 after it is dosed.

I really do not think trying to time organic carbon dosing against foods added to the tank is a worthwhile consideration.

My PO4 without dosing sits about .39-
It’s bringing it down to .31 at the moment.

Ok -so don’t tie against food added -got it-
But is the benefit of a simple bolus vs spreading it out during the day.

Also I realized an error I was making was adding in nitrate as it was really low. Prob not helping the cause.. momentarily paused that.

 

[Randy Holmes-Farley]

its effect naturally spreads out in time, but spreading it out over the light cycle limits the O2 and pH concerns.

What is the nitrate level?

 

[Faulkner’s maze]

its effect naturally spreads out in time, but spreading it out over the light cycle limits the O2 and pH concerns.

What is the nitrate level?

I can’t remember what it fell to..been dosing for awhile-right now at 4.9 -

I realize though I think with continued nitrate dosing I am allowing bacteria to feed on nitrogen vs phosphate.

Not sure though how long/much to let it ride in terms of no3/po4 ratios or nitrate gets too low..

 

[Randy Holmes-Farley]

I’d be very careful N does not get too low. Carbon dosing generally drops it much more than P since organisms contain a lot more N than P.

 

[Faulkner’s maze]

I’d be very careful N does not get too low. Carbon dosing generally drops it much more than P since organisms contain a lot more N than P.

That is my concern and will keep track of it but is it ok to dose nitrate or does that impinge phosphate absorption

I was dosing 1.6 ml that kept it at ~5 -can always to reduce to something less -

 

[Privateye]

Huh. I've never really considered the timing. We use denitrification reactors at work, but we just introduce the carbon into the incoming water at all times with a dosing pump.

I suppose what this gets into is the rate of nitrification and denitrification, which can depend on factors such as temperature. For example, how long after you feed will it take for the ammonia to be converted to nitrate? How quickly can denitrification knock it down when carbon is present? Perhaps this matters little - just thinking out loud.

 

[Randy Holmes-Farley]

That is my concern and will keep track of it but is it ok to dose nitrate or does that impinge phosphate absorption

I was dosing 1.6 ml that kept it at ~5 -can always to reduce to something less -

Dosing nitrate or ammonia is fine. It's about the only way to use carbon dosing to bring down phosphate substantially without a big drop in nitrate.

 

[Randy Holmes-Farley]

Huh. I've never really considered the timing. We use denitrification reactors at work, but we just introduce the carbon into the incoming water at all times with a dosing pump.

I suppose what this gets into is the rate of nitrification and denitrification, which can depend on factors such as temperature. For example, how long after you feed will it take for the ammonia to be converted to nitrate? How quickly can denitrification knock it down when carbon is present? Perhaps this matters little - just thinking out loud.

I'm not sure conversion to nitrate is necessary or desirable for this process, since the bacteria will be happy to use ammonia as their source of N. :)

 

[Faulkner’s maze]

Dosing nitrate or ammonia is fine. It's about the only way to use carbon dosing to bring down phosphate substantially without a big drop in nitrate.

Thanks. But if I dose (substantial) amount of nitrate will that interfere with bringing down phosphate?

 

[Randy Holmes-Farley]

Thanks. But if I dose (substantial) amount of nitrate will that interfere with bringing down phosphate?

No, not at all. Growing bacteria need both N and P. They are not interchangeable in any fashion.

 

[Faulkner’s maze]

Got it-thanks.

 

[Waldek M.]

Hello -
My question is this-currently I am trying to optimize carbon dose timing -

Right now I am dosing 1.6 ml of bacto balance and I feed 9:00, 12:00, 14:00, 16:00 a combo of pellets (morning) and then ROE and artic pods afternoon (automated)

I essentially have it so that doses are broken down nearly even 30 min and 45 min after feeding.

As I will need to decommission the mini fridge (leaking and internal temp controller not stable) that has pods/ROE I will be reverting to feeding pellets 2-3x a day instead.. with some other coral food later in the evening (don’t intend to dose after lights out).

I keep the skimmer going now at feeding.
Are there optimal time periods before /after feeding to dose and should I start with a dose right after lights on -8:00 am

Thank you for any input.

I'll share my experiences. I like and use many TM products, but Bacto Balance didn't work for me because, despite using it as directed, it always spiked my phosphate levels too much. I constantly use Lanthanum TM fed to the skimmer, plus Elimi NP from time to time, depending on the nitrate level, and I'm fine. Regarding the lanthanum, about a year after using it, I did an ICP test and the result was zero.

 

[Uncle99]

Dosing carbon has a greater effect on nitrate reduction rather than phosphate. It controlled my nitrates great, from 50ppm to 5ppm in 5 months, but I seen no effect on phosphate.

Phosphate is easier managed IMM by GFO which it will bind to, then the GFO tossed out, some can be reset.

For me RED SEA suggests their product nopox manages nitrates and phosphate, but I think they stretched the latter, or, at least, that’s what I seen during use.

 

[Privateye]

I'm not sure conversion to nitrate is necessary or desirable for this process, since the bacteria will be happy to use ammonia as their source of N. :)

Good point - I often forget that about the aerobic bacteria. I don't think the anaerobes we deal with can do that (please let me know if that's incorrect) but it would be awesome to go from NH3 to N2 without nitrification!

 

[Faulkner’s maze]

Dosing carbon has a greater effect on nitrate reduction rather than phosphate. It controlled my nitrates great, from 50ppm to 5ppm in 5 months, but I seen no effect on phosphate.

Phosphate is easier managed IMM by GFO which it will bind to, then the GFO tossed out, some can be reset.

For me RED SEA suggests their product nopox manages nitrates and phosphate, but I think they stretched the latter, or, at least, that’s what I seen during use.

Using bacto def see a difference in po4 reduction- just a lot greater in terms of NO3. So I supplement NO3 to make sure it doesn’t bottom out. I really do not like GFO as I find it unpredictable.

See if I can get the results I want -if not -I’ll reconsider…def exporting a ton of stuff in skimmer though!

 

[Faulkner’s maze]

I'll share my experiences. I like and use many TM products, but Bacto Balance didn't work for me because, despite using it as directed, it always spiked my phosphate levels too much. I constantly use Lanthanum TM fed to the skimmer, plus Elimi NP from time to time, depending on the nitrate level, and I'm fine. Regarding the lanthanum, about a year after using it, I did an ICP test and the result was zero.

I have to re-visit lanthanum-for me -it popped up twice on ICP tests -first time acceptable-2nd time really high. Less worried about fish/coral than it sticking to pumps and what not. .

Curious to what @Randy Holmes-Farley thinks of PO4 management between lanthanum (via skimmer) for long term management vs carbon dosing - which might be more viable..

I might come back to it now that I don’t shut off the skimmer and possibly dilute it 100:1 vs 40:1 RODI:lanthanum prior

 

[Randy Holmes-Farley]

Good point - I often forget that about the aerobic bacteria. I don't think the anaerobes we deal with can do that (please let me know if that's incorrect) but it would be awesome to go from NH3 to N2 without nitrification!

Aerobic bacteria use ammonia as their source of N for proteins and tons of other biomolecules.

 

[Randy Holmes-Farley]

I have to re-visit lanthanum-for me -it popped up twice on ICP tests -first time acceptable-2nd time really high. Less worried about fish/coral than it sticking to pumps and what not. .

Curious to what @Randy Holmes-Farley thinks of PO4 management between lanthanum (via skimmer) for long term management vs carbon dosing - which might be more viable..

I might come back to it now that I don’t shut off the skimmer and possibly dilute it 100:1 vs 40:1 RODI:lanthanum prior

Lanthanum is inexpensive and is inexpensive, but has some low risk to tangs that concerns me.

Controlling phosphate by organic carbon dosing is a long, slow process which typically involves dosing N. Carbon dosing also has a low risk of causing coral problems.

GFO is more expensive than these two, but is an OK way to go.

Growing macroalgae is a slow, steady process that I prefer.

All have other cons, such as potentially reducing trace elements.