Lasses Dream Build

[taricha]

I've seen weird "rebound" NO3 values (quick increases) several times from people stopping carbon dosing.
It's a bit of a puzzle.

 

[Lasse]

I've seen weird "rebound" NO3 values (quick increases) several times from people stopping carbon dosing.
It's a bit of a puzzle.

Do you know if this is mature tanks of some age. For me - its not so weird because there is a lot of organic matters - never clean sand, rocks. DSB or whats ever. But I think that we have to forget the holy truth that NH3/NH4 normally can´t be a problem in a mature tank. In my case - the NH3/NH4 coming from other sources than fish must be over 1mg/L and day. However - my nitrification seems to be fast enough in order to convert this NH3/NH4 into NO3. But - what happens if my nitrification bacteria will be wiped out of some reason?

For me - it is not either surprising that denitrification act fast if a DOC source is added. DOC is used in the cellular respiration process - not as a growth factor in first hand.

Sincerely Lasse

 

[Lasse]

This days result- I´ll rise the DOC to 12 ml 8% Ethanol a day. My dream value is just over 2 mg/L. Will see if its possible to create a rather stable reading. Its clear that the reversed DSB works as intended and that the amount of DOC/day is critical. Its also rather clear that there is a hogh NH3/NH4 production in at least my nearly 7 years old ecosystem

Sincerely Lasse

 

[taricha]

Do you know if this is mature tanks of some age. For me - its not so weird because there is a lot of organic matters - never clean sand, rocks.

Mature tanks, and I don't have much hard data - just a sense that the rebound is like you saw - faster up than expected based on feeding and what NO3 rate increases would have been in the system during time periods with no carbon dosing at all.

 

[Lasse]

Mature tanks, and I don't have much hard data - just a sense that the rebound is like you saw - faster up than expected based on feeding and what NO3 rate increases would have been in the system during time periods with no carbon dosing at all.

Do you know anything about PO4 concentrations after stop dosing DOC in these tanks?

In my case - IMO - its obvious that my variations of NO3 is depended mostly by nitrification of internal produced ammonia and dedicated internal denitrification in my reversed flow DSB/under gravel filter.

NH4/NH3 and nitrification are normally seen as not problematical in a mature tank - my observations indicate the opposite. In my case - what should happens if my nitrification process suddenly stall or get limited.

Sincerely Lasse

 

[Lasse]

Todays measurements

Sincerely Lasse

 

[Lasse]

Today

Sincerely Lasse

 

[taricha]

So what is your daily amount of ethanol input now that is currently doing a good job of leveling the NO3?

 

[Lasse]

For the moment I´ll try to tune in the dose. Of historical reasons - I dilute my ethanol to 8 % and for the moment I dose 12 ml a day . My goal is to balance around 3 ppm NO3

Sincerely Lasse

 

[taricha]

For the moment I´ll try to tune in the dose. Of historical reasons - I dilute my ethanol to 8 % and for the moment I dose 12 ml a day . My goal is to balance around 3 ppm NO3

Sincerely Lasse

So what mL/L of 8% ethanol is that?

And if you stopped ethanol for 2 or 3 days what would you guess the increase of NO3 would be? Like 3ppm/day maybe?

 

[Lasse]

The aquarium is 310 L - it means 0,039 ml 8 % ethanol per L and day

And if you stopped ethanol for 2 or 3 days what would you guess the increase of NO3 would be? Like 3ppm/day maybe?

Not a single idea - needs to be testet I will stop for one or two days soon and see if the rise will happens again (repeating test)

Sincerely Lasse

 

[Lasse]

Todays result - NO3 - 0.3 mg/L

Time for shutting off the carbon source in order to see if history repeats

Sincerely Lasse

 

[Lasse]

So - I got my latest report from Oceamo according my attempt to lower the potassium concentration from 513 mg/L to around 400. I used their new concept Oceamo correction - and yes it works well for me. I only had to do 1 larger (40 L) and after that 6 smaller ones (5 L). I get my latest result back yesteryear

Sincerely Lasse

 

[Lasse]

History repeat itself

It has rise with 2.2 mg/L NO3 - it means - 0.5 mg/L NO3-N. Converted from NH4 by nitrifikation - at least 0.5 mg NH4-N -> 0.5*18/14 = 0.62 mg/L NH4. It means a minimum production of NH4 inside the aquarium is 0.62/13 (13 hours between measurements -> around 0.05 mg/L NH4/hour. This is if all NH4 produced is converted to NO3 and no NO3 has been denitrified, Probably have som NH4 been taken up and som NO3 has been denitrified. How much - I have no idea.

However - a minimum produktion of around 0.05 mg/L NH4 per hour is - IMO - high and rise a lot of discussion about nitrification rate and other factors in mature aquariums. My results - that's seems to be repetable - indicate that ammonium production in mature aquariums are underestimated in the reef community , So also nitrification rates, In new aquariums - the most of the ammonium production is driven by the amount of food and normally only 2 - 3 hours after feeding. In mature aquariums - IMO - the ammonification is bacteria driven and take place 7/24. This means that the nitrification must handle a rather constant load of ammonium and if - it stops of some reasons - total ammonium (NH4/NH3) can build up and sooner or later also the toxic form NH3.

The nitrification can be tricky in saltwater because oxygen concentrations is nearly 1 - 1.5 mg/L lower than in freshwater of the same temperature. Oxygen concentrations is important for nitrification rate. During daytime - with a lot of photosynthesis - O2 concentrations is of no importance - IMO - but during night time - it could be critical low

In my case - I have solved the oxygen problem with help of oversized skimmer, oxydator and reverse refugium

Sincerely Lasse

 

[Lasse]

NO3 today - still rising

Sincerely Lasse

 

[Aqua Man]

However - a minimum produktion of around 0.05 mg/L NH4 per hour is - IMO - high and rise a lot of discussion about nitrification rate and other factors in mature aquariums.

How many fish do you have ? If I remember correctly, you did have a good population of various fish!!

 

[Lasse]

I´m sorry to say - my population are not so large anymore - maybe 25 - 30 fish. There was some death back in November last year.

Sincerely Lasse

 

[Lasse]

This evening - not so much rising during day. Decide to stopp dosing during next 24 hours too

Sincerely Lasse

 

[taricha]

NO3 today - still rising

Sincerely Lasse

This looks like in the first day after halting ethanol, NO3 rose somewhere around ~3-4ppm per day both times.

This would be 0.68-0.90mg/L Nitrogen.
If we put this in food input, it would say 4.3-5.6mg/L protein per day.

I don't know if you could estimate your protein/day input. The above numbers, like you said, seem large for NO3 production rate from nh3.

 

[Lasse]

I feed with around 20 g Ocean Nutrition Adult Frozen Artemia - protein content around 5%, Around 9 g Frozen Cyclops - protein content around 3.4 %. This means a daily input of around 1.3 g protein Normally - the N content in protein is around 16% - this means that I feed with around 208 mg N/each day - it means in my 310 L -> 0.7 mg/L N a day. Normally - feeding with frozen natural food and to cold-blooded animals as fish- the bioaccumulation of given food is around 20 %. This means that around 42 mg N will be as fish biomass and 166 mg N out in the water as mostly NH4 -> 213 mg NH4 -> 0.69 mg NH4/L If all of this was converted into NO3 by nitrification - it correspond to around 2,3 mg NO3/L

If I look at the figures I got today - my rise NO3 during 2 days (around 4 mg/L - 48 hours) corresponding to expected increase in nitrate content - but the rise this time has been half the rise of the first time (13/2). However since that day I have introduce a new bunch of chaeto into my refugium - before it was more or less empty. I suspect that the difference in rise of NO3 after stopping DOC dosing between t 13/2 and this run can depend on the growth of my chaeto. I´m sorry - I introduce another parameter into this mess but - IMO - half the produced NH4 in my system is due to internal production.

Before anyone compare with his/hers own system - its important to underline that my system is only fed frozen natural feed which makes the protein content per gram low due to high water content. If you feed with high-quality dry food, the protein content is between 7 - 10 times higher. My feeding of approx. 30 g of frozen wet food corresponds to a feeding of dry food between 4 and 3 grams a day

This means that a fast rise of NO3 after quitting DOC dosing can be solely depending on the feed but in my case its probably not that way. I seem to have a high internal production of N

However - these documented findings raise a concern that we can´t just - as done in the past - exclude fast happening NH3 toxifications if the nitrification cycle just stop. My system release at least around 0.7 mg/L NH4/NH3 a day - and this should not be accumulated to the next day- If I put these figures into this calculator - I get a production of around 0.06 free ammonia (NH3) a day

Measurements of today. They are done with Hanna High Nitrate checker. The absolute values should be considered with caution, but the trend is quite clear. My measurements do not have scientific precision, but they can at least give you a hint of how it works. Last comparison I done with a more scientific measurements shows 5,16 mg for that analyse and Hanna checker shows 6.2. mg/L NO3. Its enough precision for me

Sincerely Lasse