Mini cycle

[taricha]

I need @taricha to jog my memory of out many discussions and experiments on sand beds. In short, they are complicated ecosystems.

If you carefully remove water from the sand (pore water) without mixing it with water from above the sand bed, the water between the sand grains contains ammonia and a higher concentration of phosphate. Dissolved oxygen is definitely lower by several ppm. i think the alkalinity and pH are also different from the water above the sand bed. The total amount of pore water compered to the total amount of aquarium water is small and alone would not cause a large ammonia spike. A sudden release and subsequent digestion of organic matter from the sand when stirred up might cause ammonia to rise (I have not done this).

So sandbeds can be found to contain ammonia, but the amounts are usually too small to explain nuisance growth, and way way too small to create a tank-wide elevated ammonia level of concern.
I found that I could test porewater and get stuff like 0.2 to 0.4 ppm total ammonia higher than the zero in the tankwater. pH in my porewater is always at the aragonite buffer of 7.5-7.6 because decomposing organics in very low flow lowers the pH with CO2 until the sand buffers it. The oxygen level is zero at some depth (some sulfide smell can appear), and above zero in the upper levels. Phosphate (and Fe) in my old sandbed was significant. PO4 of 0.10-0.15 in the water, but 1-1.5ppm PO4 in the porewater. Fe was found to be present in the fine particle dust in my sand at nearly the same levels expected in living cyano cells.

Yeah, the Seneye would be a device to detect ammonia in the sand. Stirring the sand and catching a whiff of ammonia might work. The “might” qualification is based on not mixing too much above sand water with the pore water. The merit in this idea for me is that the sand bed as an ammonia generator could be part of or the entire explanation for why nuisance algae grow immense populations on sand

I tried squeezing N out of old sandbed grunge every imaginable way (including some heated acidic digestions), looking for enough N that could drive nuisance growth and eventually came to the conclusion that it's squeezing blood from a stone. If you work hard enough, you can measure some N but the amounts are so tiny you'll never get good nuisance growth off of that N. But P and Fe? plenty there to sustain any organism capable of exploiting it.

I picture their appetites like those of my dogs: insatiable. If more food becomes available, the more of them there are. The aquarium sand bed probably does not have the intensity of organic matter raining down on it like that in the ocean or on a reef.

Agree - I simply don't see any pathway nor evidence of long term storage/accumulation of large amounts of N.
The exceptions prove the rule here: a big fish like to poop in one corner and cyano grows there, or a pile of dead GHA slimes over with cyano are the sort of clear organic N inputs you need to drive good nuisance growth with old sand.
Not just my sand is 10 years old so there's years of fish food/poop nitrogen stored in there. That stuff has been exploited long ago.

. @taricha I think has done some experiments to tease out the proportions of ammonia processed via photosynthetic organisms and nitrifyers - or at least had some clever ideas on the subject. It’s been years since.

In a light driven system (which is every reef tank) - I estimate the end state is probably around 90% ammonia consumption by photosynthetic stuff, and <10% by nitrifiers. This was the case in my sandbed and system, and sand I took from some LFS had roughly the same nitrifying capacity as my own.

Yes, old rocks might be well populated with ammonia consumers after ten years, In an aquarium where water flow is relatively poor, the rock surfaces might have thick biofilms that might act as a barrier to bringing ammonia and CO2. Biofilms are stick and all sorts of stuff sticks to them, adding more resistance to the influx of ammonia. Sometimes old isn’t so good

We can think about some failure modes that might apply here.
Old sand kept and re-used. It's unlikely that the same surfaces that were exposed before and thus had all the nitrifying biofilm are still exposed now in the new sytem. biofilms aren't evenly distributed in the sand and most of the nitrifiers got buried.
similarly but not as extreme with the rocks. Nitrifiers likely seek out the best surfaces on rocks and concentrate there, with the best flow of aerated water across the surface. pick up all the rocks and put them in a new system. Maybe the "good" surfaces don't get good flow anymore. This is very temporary - biofilms will adjust in a few days.
But what if your system is 90% ammonia uptake from photosynthetic organisms like corals and anemones. And you move them all over to a new system and something about the change has them really ticked off. What's their uptake now? I bet a lot smaller. Maybe zero. Maybe even negative, if they close up tight and squeeze out some chemicals in distress, then your ammonia consumers may now be releasing nitrogen

Add in the fact that all those organisms will release slime = digestible organic carbon. Add in that some dead anemones and urchin have been found in the sand. So you have lots of decaying organic matter. The decaying organic matter in addition to releasing some N, is also releasing a lot of digestible organic carbon. This lowers the O2 level. You don't have to push O2 to zero to really slow down nitrification, you can probably slow it way down at 30-50% of max O2.
If the nitrifiers are fighting with heterotrophs for oxygen in an environment with lots of organics floating around, they aren't gonna win that. Heterotrophs do. Also the skimmer has been offline for some of this time.
If the majority of previous ammonia uptake was from softies and nems that are now really ticked off, they probably aren't doing the job either.
So who exactly is supposed to be consuming all the ammonia now? maybe nobody can in this little (mini-cycle) scenario.

 

[Dan_P]

So sandbeds can be found to contain ammonia, but the amounts are usually too small to explain nuisance growth, and way way too small to create a tank-wide elevated ammonia level of concern.
I found that I could test porewater and get stuff like 0.2 to 0.4 ppm total ammonia higher than the zero in the tankwater. pH in my porewater is always at the aragonite buffer of 7.5-7.6 because decomposing organics in very low flow lowers the pH with CO2 until the sand buffers it. The oxygen level is zero at some depth (some sulfide smell can appear), and above zero in the upper levels. Phosphate (and Fe) in my old sandbed was significant. PO4 of 0.10-0.15 in the water, but 1-1.5ppm PO4 in the porewater. Fe was found to be present in the fine particle dust in my sand at nearly the same levels expected in living cyano cells.

I tried squeezing N out of old sandbed grunge every imaginable way (including some heated acidic digestions), looking for enough N that could drive nuisance growth and eventually came to the conclusion that it's squeezing blood from a stone. If you work hard enough, you can measure some N but the amounts are so tiny you'll never get good nuisance growth off of that N. But P and Fe? plenty there to sustain any organism capable of exploiting it.



Agree - I simply don't see any pathway nor evidence of long term storage/accumulation of large amounts of N.
The exceptions prove the rule here: a big fish like to poop in one corner and cyano grows there, or a pile of dead GHA slimes over with cyano are the sort of clear organic N inputs you need to drive good nuisance growth with old sand.
Not just my sand is 10 years old so there's years of fish food/poop nitrogen stored in there. That stuff has been exploited long ago.


In a light driven system (which is every reef tank) - I estimate the end state is probably around 90% ammonia consumption by photosynthetic stuff, and <10% by nitrifiers. This was the case in my sandbed and system, and sand I took from some LFS had roughly the same nitrifying capacity as my own.



We can think about some failure modes that might apply here.
Old sand kept and re-used. It's unlikely that the same surfaces that were exposed before and thus had all the nitrifying biofilm are still exposed now in the new sytem. biofilms aren't evenly distributed in the sand and most of the nitrifiers got buried.
similarly but not as extreme with the rocks. Nitrifiers likely seek out the best surfaces on rocks and concentrate there, with the best flow of aerated water across the surface. pick up all the rocks and put them in a new system. Maybe the "good" surfaces don't get good flow anymore. This is very temporary - biofilms will adjust in a few days.
But what if your system is 90% ammonia uptake from photosynthetic organisms like corals and anemones. And you move them all over to a new system and something about the change has them really ticked off. What's their uptake now? I bet a lot smaller. Maybe zero. Maybe even negative, if they close up tight and squeeze out some chemicals in distress, then your ammonia consumers may now be releasing nitrogen

Add in the fact that all those organisms will release slime = digestible organic carbon. Add in that some dead anemones and urchin have been found in the sand. So you have lots of decaying organic matter. The decaying organic matter in addition to releasing some N, is also releasing a lot of digestible organic carbon. This lowers the O2 level. You don't have to push O2 to zero to really slow down nitrification, you can probably slow it way down at 30-50% of max O2.
If the nitrifiers are fighting with heterotrophs for oxygen in an environment with lots of organics floating around, they aren't gonna win that. Heterotrophs do. Also the skimmer has been offline for some of this time.
If the majority of previous ammonia uptake was from softies and nems that are now really ticked off, they probably aren't doing the job either.
So who exactly is supposed to be consuming all the ammonia now? maybe nobody can in this little (mini-cycle) scenario.

Thanks for the corrections, additions, and perspectives!

 

[Lasse]

Agree - I simply don't see any pathway nor evidence of long term storage/accumulation of large amounts of N.

I´m not sure of this. Accumulation of NH3/NH4 especially in low oxygen environment is known from nature. A large part of the worlds fishery is depended on this ability to produce and store huge amounts of NH3/NH4 and during certain circumstances will this be transported up to levels there these nutrients and the sun produce huge amounts of phytoplankton which are the base for many important fishing grounds. This is known as upwelling.

In an experimental anaerobic tank we had in a waste water plant I work in was the effluent rich in NH3/NH4. We measured around 2-3 mg/L NH3/NH4 into the tank and nearly the same in the outlet on a regular base during the 5 years I work there. However - the interesting part was the measurements we get from the middle of the tank. The tank was basically a tank of water - inflow in the bottom and outlet in the top. In the tank was a lot of plastic net placed as substrate for bacteria. In the middle we read on a regular base up to 200 mg NH3/NH4. No one could explain this but the measurements was repeated many times with good equipments. The whole tank was anaerobic.

I´m rather sure that I have a similar situation in my reversed flow DSB. Not so extreme but never the less similar. I have not measured the NH3/NH4 in the plenum - I have not have any equipment for that until now. I will measure this in the future some time.

You don't have to push O2 to zero to really slow down nitrification, you can probably slow it way down at 30-50% of max O2.

In fresh water is the lower limit for the first step NH3/NH4 -> NO2 around 2-3 mg/L and for the second step (NO2->NO3) around 5 mg/L. It is probably nearly the same for salt water. It means that second step run in trouble already at around 70 % saturation at 26 degree C (around 79 F). 100% saturation in 35 PSU saltwater at 26 degree C is 6.66 mg/L (source)

NH3/NH4 measurements in my tank during march. Hanna Marin Master.

Taking into account the accuracy (error bars) you can say that I'm probably around 0.1 - 0.12 mg/L NH3/NH4 on a regularly base

Sincerely Lasse

 

[taricha]

In the middle we read on a regular base up to 200 mg NH3/NH4. No one could explain this but the measurements was repeated many times with good equipments. The whole tank was anaerobic.

Fair enough. Ammonia can be driven quite high in some anaerobic situations. Maybe an aragonite sandbed is one of them, but I'd be really surprised.

I did a similar thing once with a half liter bottle of tank water spiked to ~100 ppm NO3. Then I added vodka gradually to try to lower the NO3 with no aeration. I ended up with about 1-ish ppm ammonia. So mine was not an efficient ammonia generator.

In fresh water is the lower limit for the first step NH3/NH4 -> NO2 around 2-3 mg/L and for the second step (NO2->NO3) around 5 mg/L. It is probably nearly the same for salt water. It means that second step run in trouble already at around 70 % saturation at 26 degree C (around 79 F).

Great info. Thanks.

 

[Lasse]

I did a similar thing once with a half liter bottle of tank water spiked to ~100 ppm NO3. Then I added vodka gradually to try to lower the NO3 with no aeration. I ended up with about 1-ish ppm ammonia. So mine was not an efficient ammonia generator.

It is surprising that you get NH3/NH4 in that bottle - it is not a known "waste" from denitrification (its N2 instead) The NH3/NH4 you get come from the organic matter you have in the bottle - if it is low - you get low NH3/NH4 production. But if it is waste water - as in my example - the organic load is high. In the bottom of my sand bed it should also be rather high because of the water that I pump into the plenum contain a lot of particular organic matter (POM). The addition of dissolved organic carbon (my ethanol addition) would also speed up that breakdown of this accumulated POM. My plenum is not anaerobic because I have positive ORP potential - around + 2-300 mV.

I know that this system is a huge CO2 producer. A week ago my pump that supplying the plenum with aquarium water stopped without me noticing. The same day I observed that my daily pH peak was around 0.15 higher than normally - did not understand why.

Next morning I noticed that my pH and ORP in the plenum (below the sand bed had declined) - this is for me a signal that I do not get enough of water into the plenum

As you can see - the lowest peak is around 12:00 2024-04-20. At that time I succeeded to change tte pump and started the new one

Both pH and ORP rise in the plenum - but what happens with the pH in the sump. It was 12:00 and the photosynthesis had start to rise my pH (consumption of CO2)

It decreased with around 0.7 in pH. It was rather much of internal CO2 stored in the bottom of my DSB - transported up to the aquarium when I started the pump. I guess that I also released a lot of hydrogen sulphide too but nor enough to sense any smell. I did not do a NH3/NH4 measurement in the DT because lack of reagents

Sincerely Lasse

 

[brandon429]

Taricha

Can you link an example you've seen in any other thread where a cured live rock system couldn't resolve ammonia after eight days

 

[BeanAnimal]

Taricha

Can you link an example you've seen in any other thread where a cured live rock system couldn't resolve ammonia after eight days

This feels like a deflection. You asserted for 4 pages there is no such thing even though this thread is an example along with numerous people explaining to you why it can and likely did happen.

Why should somebody have to go search for more examples simply because you do not agree with the accepted fact? How is this thread any different than the others with the same facts and outcome?

 

[Cell]

No additional supporting evidence allowed!

 

[brandon429]

Thought tank had cycled, now not so sure

I have a red sea max nano 75L, I used old dried out live rock for the scape and sand substrate, my own RO water so zero tds. Plan was to do a fishless cycle using seachem stability, the tank was started cycling on the 6th sept, it looked like it was cycling ok so on the 15th sept to check I...

www.reef2reef.com

check that out. Umpires said 1 ppm means cycled there.

but .66 here cannot be, no, cannot even with perfect pictures posted anytime an update is ran here.


going off test kit levels assumed allows for changing subjectivity in cycling calls we see.

but counting the number of days to a cycle end date per cycling type (new cycling science) is objective, and somehow always knows what the pics of the tank are going to look like

this tank here is a live rock transfer, that's zero days wait to readiness.

 

[BeanAnimal]

No additional supporting evidence allowed!

Supporting evidence is always fine. However, one has to suspend disbelief and 6.5 pages of pivoting to miss the context for which it is being asked here. This pattern plays out each time he is shown to be incorrect. There is NEVER enough for him to admit being incorrect, just deflections and pivots.

Incorrect about what you ask?
Post #2 in this thread

There is no mini cycle in reefing your system is fine...

....Ammonia events resolve in under fifteen minutes since the rocks remained cycled.

Proof and explanation was provided but here he has pivoted again in post #129, ignoring all evidence in this thread, and citing another thread that has absolutely zero context to the situation "mini cycle" here.

 

[BeanAnimal]

Thought tank had cycled, now not so sure

I have a red sea max nano 75L, I used old dried out live rock for the scape and sand substrate, my own RO water so zero tds. Plan was to do a fishless cycle using seachem stability, the tank was started cycling on the 6th sept, it looked like it was cycling ok so on the 15th sept to check I...

www.reef2reef.com

check that out. Umpires said 1 ppm means cycled there.

That is a new tank with dry rock 25+ days in where the OP dumped 2ppm ammonia into the tank. It has absolutely no bearing on any aspect of the OPs situation or this thread where a system was transferred and ammonia rose on its own.

 

[Garf]

but .66 here cannot be

I thought the OP reported that the hanna rose to 2.3?

 

[brandon429]

until there's good seneye data on several transfers and what detritus causes in them, charting resolve rates and max peak intervals, I'm having to make patterned-based guesses on ammonia status during tank transfer.

Taricha's stated possible mechanism sounds plausible I had just wanted to know if it's part of a pattern out there, if he's seen this before recently

 

[brandon429]

2.3 makes my case much better (because that's an unbelievable reading level, adulterants or reagent errors are in play here) thank you for that, I did not see that rise part.

I'm more positive than ever this is a false read and about to be my #1 example knowing that detail, but only after we track out the perpetual doubt for the next twenty pages. I'm going to wait until the OP agrees that there's no ammonia distress here, then compare the number of pages that resolve required vs applying rules of skip cycle tank transfer work here.

Did I ever get my nh3-stated test verification ran on the LFS reef with the test that made this thread?

 

[alicia24]

I thought the OP reported that the hanna rose to 2.3?

Yes 2.23 to be exact

 

[alicia24]

2.3 makes my case much better thank you for that, I did not see that rise part.

I'm more positive than ever this is a false read and about to be my #1 example knowing that detail.

Not a false read. As I wrote in here my DT (different tank) is 0.05 so its not the hanna checker at fault.

 

[Garf]

2.3 makes my case much better (because that's an unbelievable reading level,

This reminds me of an interaction we had 18 months ago, I can post a link if required.

 

[brandon429]

ok let's see it I dont recall. consistency in evaluation is what I'm aiming for, so if I was inconsistent in assessment for live rock systems last year I would like to know. something really out of line would need to be here to cause this, a continued input source would be required.

 

[BeanAnimal]

2.3 makes my case much better (because that's an unbelievable reading level, adulterants or reagent errors are in play here) thank you for that, I did not see that rise part.

So you again are not wrong because the the OP and her test kit cant be trusted?

I'm more positive than ever this is a false read

That makes no sense. Her readings kept going up with each test and her other tank didn't.

OP agrees that there's no ammonia distress here

That is yet another deflection and pivot. The ammonia here is verifiable and explainable with or without distress and was rising. The pH was low and hopefully no stress occurred. When do you just admit to being incorrect? Honestly?

 

[brandon429]

can we get a tank pic

in any true impending crash, what those readings mean if they were true (rising uncontrollably) you get gray water as microorganisms die first and begin the loss cascade

can we get a tank pic for today looking for closed corals, gray water, bad smell, pending crash

the only mechanism that can cause these readings if true is too much bioload for the surface area (pics show us that's not the case) or a continued input source far beyond what the dosing ammonia thread shows people inputting per day, and reefs can process quite a bit of ammonium chloride in 15 mins we can see.

can you take a test kit reading, and actually post the readout of the kit today as a pic