Crazy kH consumption?

[Kungpaoshizi]

Here's something interesting...

Therefore the variation of pH could not only be used to control the nitrification time but also to judge whether the alkalinity was enough or not. On the basis of this, the fuzzy controller of nitrification in SBR was constructed. When discussing the influence of pH on nitrification rate the composition and concentration of alkalinity must be considered or else the results may be incomprehensive. And to some extent the influence of alkalinity on nitrification rate was more important than pH.
http://www.ncbi.nlm.nih.gov/pubmed/12906274

 

[Kungpaoshizi]

You have found that bacteria respond to alkalinity?
I've not heard that before and cannot understand why it would be since they do not use it (unless you mean photosynthetic cyanobacteria, which do consume CO2 and might get it from bicarbonate).

Now you've got me interested.. lol (probably boring to most, but I keep thinking of your statement)

The more I'm looking into this, the more there is a direct correlation from nitrification rates to available alkalinity to prevent ph/alk crashes.


The more I think about it too, the more it fits the bill as to the larger swings I saw when initiating 2 part dosing. (aside from the later demand from corals as they're growth sped up)

*edit
Ha, there's even a calculator utilizing the formulas (page doesn't work though)
http://www.dep.state.pa.us/dep/deputate/waterops/Redesign/PAGES/calculator.htm

Apologies for semi-hijacking the thread ReefMadScientist, I'll create my own thread

 

[Randy Holmes-Farley Verified Community Expert]

'did not say anything to suggest that nitrification could ever be alkalinity limited or impacted'?
Doesn't that graph say it all?
I see a clear difference between their numbers at 7.8 ph and 8.3.
Of course the difference of fw to sw COULD mean the difference, but I imagine when talking about bacterial processes it's probably similar. Look at the redfield ratio compared to carbon dosing. It's not applicable to it, but we have all seen it to be very similar. (some even quote the redfield ratio when discussing carbon dosing)

The graph doesn't have alkalinity on it, so sorry, no. lol

I already stated that it is well known that nitrification rates in the ocean decrease slightly as the pH is lowered from 8.1 to 7.8. That is with the same alkalinity of NSW.

I'm not sure why you have such a bee in your bonnet over this. Reef tanks do not appear tosuffer from excessive amonnia at any normal pH or alkalinity.

 

[Randy Holmes-Farley Verified Community Expert]

Here's something interesting...

Therefore the variation of pH could not only be used to control the nitrification time but also to judge whether the alkalinity was enough or not. On the basis of this, the fuzzy controller of nitrification in SBR was constructed. When discussing the influence of pH on nitrification rate the composition and concentration of alkalinity must be considered or else the results may be incomprehensive. And to some extent the influence of alkalinity on nitrification rate was more important than pH.
http://www.ncbi.nlm.nih.gov/pubmed/12906274

Sorry again, not so interesting. I think you perhaps misunderstand the last sentence and left out the critical sections above this one.

They were trying to control the nitrification time in this brewery waste (of little seeming relevance to reef tanks since the alkalinity and pH ranges in brewery waste are unlike reef aquaria) and found that in some uncommon situations when alkalinity was "excessive", they were unable to easily control the pH (it would rise), and so they couldn't control the nitrification rate by pH. That is what they mean, not the alkalinity itself controlled nitrification; alkalinity impacted the pH (and hence denitrification) in ways their simple base adding controller couldn't control.

They say this:

"When bicarbonate alkalinity was deficient or sufficient, the descending type happened. If alkalinity was deficient, the pH decreasing rate got slower when nitrification nearly stopped; if alkalinity was sufficient, at the end of nitrification pH turned from decrease to increase. This was the most common situation and pH could be used to control the end of nitrification. When alkalinity was excessive, the rising type happened, pH was increasing at nearly a constant rate during and after nitrification and could not be used to control the nitrification time..."

 

[Randy Holmes-Farley Verified Community Expert]

Now you've got me interested.. lol (probably boring to most, but I keep thinking of your statement)

The more I'm looking into this, the more there is a direct correlation from nitrification rates to available alkalinity to prevent ph/alk crashes.


The more I think about it too, the more it fits the bill as to the larger swings I saw when initiating 2 part dosing. (aside from the later demand from corals as they're growth sped up)

*edit
Ha, there's even a calculator utilizing the formulas (page doesn't work though)
http://www.dep.state.pa.us/dep/deputate/waterops/Redesign/PAGES/calculator.htm

Apologies for semi-hijacking the thread ReefMadScientist, I'll create my own thread

Larger swings in what?

I don't really know what you are talking about here, but it is well known that nitrification depletes alkalinity and denitrification adds to it (and by exactly how much). If you are cycling a tank with a lot of ammonia, alkalinity can get depleted and pH can be low.

In a normal reef tank, where you are watching alkalinity and possibly pH, there's not any reason to be concerned about the effects of those on nitrification.

 

[Kungpaoshizi]

Larger swings of alk when starting dosing alkalinity~

Though you say the chart doesn't have alkalinity on it, what I see is not necessarily ph but 'alk+co2 and +/- substances'.
Again, I guess I just find the little things interesting..
Hope I didn't bore ya!

I'm one of those people who is shown 2 nickels, and asked a question that starts with 'we know they weigh the same' but I see nicks and scratches in one and not the other and realize, no they don't!

 

[Randy Holmes-Farley Verified Community Expert]

Larger swings of alk when starting dosing alkalinity~
!

And you are attributing that to bacterial processes?

I just don't see that being significant in a cycled tank.

You think you suddenly accelerated nitrification by adding more alkalinity? How? Where did the extra ammonia come from to allow more nitrification?

 

[Randy Holmes-Farley Verified Community Expert]

FWIW, to deplete the alkalinity by the equivalent of 1 dKH, you need to convert 3.1 ppm of ammonia into nitrate. It seems unlikely you had that amount of available extra ammonia present.

Here's the calculation:

1 dKH of alkalinity = 0.36 meq/L of alkalinity

1 mole of ammonia converted into nitrate depletes 2 moles of alkalinity, so 0.18 mmoles of ammonia must be converted, or 3.1 ppm of ammonia (making 11 ppm of nitrate).

So if the swing you saw was 1 dKH, you'd had to have had more than 3 ppm of ammonia available for increased nitrification.

 

[Kungpaoshizi]

Don't think that was the case.. What did you think I meant originally when you said you didn't know bacteria were influenced, let alone use, alkalinity?
Now I'm confused...

 

[Randy Holmes-Farley Verified Community Expert]

Don't think that was the case.. What did you think I meant originally when you said you didn't know bacteria were influenced, let alone use, alkalinity?
Now I'm confused...

The bacterial process that seem to deplete or produce alkalinity in reef tanks are:

ammonia to nitrate conversion (depletes it)
nitrate to organic tissue (as in macroalgae, ATS, or organic carbon dosing in aerobic settings) (adds to it)
sulfur denitrators (deplete alkalinity)
ammonia to N2 in denitrification (adds to alkalinity)

Overall, assuming you do not use a sulfur denitrator:

1. If nitrate is increasing, alkalinity is being steadily depleted at a rate of 1 dKH per 11 ppm of nitrate
2. If nitrate is decreasing for any reason except water changes or sulfur denitrator, the exact reverse of 1 is true
3. If nitrate is steady (at any level), then these processes exactly offset and there's no net impact on alkalinity.

Aside from these and related nitrogen processes, there's very little that bacteria do in reef tanks that can impact alkalinity.

 

[Randy Holmes-Farley Verified Community Expert]

Don't think that was the case.. What did you think I meant originally when you said you didn't know bacteria were influenced, let alone use, alkalinity?
Now I'm confused...

What I meant by those words specifically (IIRC) is that I do not know of any bacterial processes (aside from photosynthetic cyanobacteria) that are altered in reef tanks by changes in alkalinity alone (not via indirect pH effects) since they do not "use" bicarbonate or carbonate for the most part, and when they do, it is not a limiting factor in their growth (bacteria that get energy from inorganic chemical processes must get' CO2 from somewhere, but alkalinity seems to not be a limiting factor in a reef tank for these bacteria, at least that I have ever seen evidence of).

Some do things that impact alkalinity (like nitrification and denitrification), but the reverse is not true as best I know.

 

[mm.reefs]

...
If not then you are going thru a growth spurt.
Sit back and enjoy everything is perfect and acros are growing
...

I too have noticed this "growth spurt" events in my tanks, in sync with excellent health and vivid coral colors. Then after a week or so comes the temporary lowering/imbalances of Alk/Ca values, I guess when the daily set dosages do not match with the coral growth demand.

 

[Kungpaoshizi]

What I meant by those words specifically (IIRC) is that I do not know of any bacterial processes (aside from photosynthetic cyanobacteria) that are altered in reef tanks by changes in alkalinity alone (not via indirect pH effects) since they do not "use" bicarbonate or carbonate for the most part, and when they do, it is not a limiting factor in their growth (bacteria that get energy from inorganic chemical processes must get' CO2 from somewhere, but alkalinity seems to not be a limiting factor in a reef tank for these bacteria, at least that I have ever seen evidence of).

Some do things that impact alkalinity (like nitrification and denitrification), but the reverse is not true as best I know.

I think it would probably go hand in hand. If alkalinity is required for the process, just as algae's metabolism can adjust to nutrient-rich or poor scenarios, bacteria have always been tougher! Please do let us know though if you hear anything in some new research. Looks like there's a few new publications out there.

 

[Randy Holmes-Farley Verified Community Expert]

I think it would probably go hand in hand. If alkalinity is required for the process, just as algae's metabolism can adjust to nutrient-rich or poor scenarios, bacteria have always been tougher! Please do let us know though if you hear anything in some new research. Looks like there's a few new publications out there.

Just bear in mind that bacteria are not "using" alkalinity they way they use a nutrient. Some (the nitrifiers) produce a waste product (H+) that destroys alkalinity. Those are quite different concepts with different implications for what impact elevated alkalinity may have on them.

 

[Kungpaoshizi]

Just bear in mind that bacteria are not "using" alkalinity they way they use a nutrient. Some (the nitrifiers) produce a waste product (H+) that destroys alkalinity. Those are quite different concepts with different implications for what impact elevated alkalinity may have on them.

Right, that's what I was getting from the wastewater info. Good food for thought though.
I might just have to setup a few tanks to see what I can observe at different alk levels. Doubt it's significant differences but it would be curious to see what the results are. It makes me wonder what other impacts it could have. (along with 247 other thoughts lol)

 

[Randy Holmes-Farley Verified Community Expert]

OK, let us know what you find.

Happy Reefing.

 

[ReefMadScientist]

@Randy Holmes-Farley

Is it possible for a coral "boom" to happen and you absorb a ton of alkalinity and then all of a sudden....it stops?

So at the beginning of this thread I was not dosing enough. I was around 28ml per day and finished to 62ml per day (weeks of adjustments). So now that I had my tank steady at 8.4dkh I decided to not test ONE DAY.

Today, I am at 10.84 dkh. I have almost had it with this psychotic tank. I have tested multiple times with various test kits.

So what I have done over the last week. I used 2tbs. of GFO to remove some excess PO4 I had. Only ran it for 24 hours.

I did a 20gallon water change of Red Sea Coral Pro. Could that have spiked my alkalinity and, if so, do I just turn off my doser or leave it set on 62ml per day? Not sure if the alkalinity will drop on its own since the water change.

 

[ReefMadScientist]

2015-09-23 21:09 Magnesium 1245 added 3.75 cups to 1350 (next two days)

2015-09-23 20:59 Calcium 400

2015-09-23 20:52 Nitrate 5

2015-09-23 20:47 Phosphate 0

2015-09-23 20:28 Alkalinity 10.84 (62ml > 0ml to let it fall.)

2015-09-20 17:41 Calcium 395 (36ml > 39ml)

2015-09-20 17:34 Nitrate 7.5

2015-09-20 17:18 Alkalinity 8.4

2015-09-20 17:18 Phosphate 0.05 (Ran 2tbs of GFO)

2015-09-18 16:44 Alkalinity 8.4 (Yesterday did a 20g water change)

2015-09-18 16:44 Phosphate 0

2015-09-17 16:44 Water Change 20 (20 gallons)

2015-09-16 20:18 Alkalinity 7.95

2015-09-15 20:51 Calcium 400 (33ml > 36ml)

 

[ReefMadScientist]

@twilliard @Russ265 See Above.

Correction from above

2015-09-23 20:28 Alkalinity 10.84 (62ml > 40ml to let it fall slowly.)

Anyone please feel free to throw in your thoughts. I just added the two above because I know they are active

Guys, do you think my Mg falling may have a weird affect on my Alkalinity or do you think it was the 20g water change?

Its strange because my Calcium is correctly moving upwards since I upped my ML's per day and has stayed steady compared to the Alkalinity.

As for Magnesium, On September 6th I was at 1350ppm and today 1245ppm. I have never seen Mag drop that much within two weeks.

 

[Russ265]

@twilliard @Russ265 See Above.

Correction from above

2015-09-23 20:28 Alkalinity 10.84 (62ml > 40ml to let it fall slowly.)

Anyone please feel free to throw in your thoughts. I just added the two above because I know they are active

Guys, do you think my Mg falling may have a weird affect on my Alkalinity or do you think it was the 20g water change?

Its strange because my Calcium is correctly moving upwards since I upped my ML's per day and has stayed steady compared to the Alkalinity.

As for Magnesium, On September 6th I was at 1350ppm and today 1245ppm. I have never seen Mag drop that much within two weeks.

time to monitor daily. if the tank is indeed that demanding i would look in to a doser.
i generally dont see mag drops like that unless you switched salt, or if the salt you are waterchanging with got damp/unmixed in the box or bucket.