Nitrate

[KoiCop]

JR . . .

Yes, one can reverse test it and show the nitrate going up, then back down, but that doesn't ID the causation.

And since vsound's idea that small anaerobic pockets in the TT/baki provide for denitrification which produces nitrogen gases which then volatize doesn't appeal to me, that leaves far-infared radiation to be considered.

[moikoi]

i use the AP drop test and the reading always been 0

[JasPR]

Don, that makes no sense to me? submerged filters would have far more potential for anaerobic proliferation than oxygen rich and clean TT media. If I pull out the plastic media from one of my towers it will be stained brown but clean as a whistle otherwise. The base is filled with clean water up about 26 inches in an eight foot tower. There is no point in rinsing it as it IS being rinsed 24 X 7 and no waste or organic is evident. On the other hand, we can rinse one of my submerged Jmats and you will get LOTS of organic mulm, the natural home of anaerobic bacteria species ( low oxygen leading to anaerobic proliferation , leading to decay, leading to lower oxygen, leading to more anaerobics). Anaerobic bacteria exist in two ways in a filter setting, 1) as a member of a nitrifying dominate community located at depth or dispursed as a clean up crew in all areas of the film. 2) in an environment that favors them exclusively- slow moving water, rich in organic sediment and resulting in less than saturated water conditions. I could see this type of mix easily set up in a BB, but I have trouble appreciating it occurs in a TT MORE than in a mulm rich BB? JR

[Erns]

What effect will lot of rain have on the nitrate reading? We are now in our 'winter' and some times it will rain non stop for 14 days at a time. Is rain water not rich with nitrogen?

[JasPR]

That's a big subject- could have effects on temperature, pH and even mineral content. I do think it could have a minor disrupting effect under the right circumstances. But biofilm has the ability to handle 'new load' in two ways. As long as oxygen and pH are not issues, the film will either expand in individual cells size to meet the need ( a very quick process) OR produce more cells to met the new carrying capacity need ( a slower process).
But nitrate 'at the end' of the conversion process is just that, the end of the conversion possibilities. So water change ( important for many reasons) or plants ( not practical at all in a real koi pond). So like any other challenge we face- test, and know the enemy! JR

[KoiCop]

Quote: Originally Posted by JasPR I could see this type of [anaerobic] mix easily set up in a BB, but I have trouble appreciating it occurs in a TT MORE than in a mulm rich BB? JR

Couldn't agree more -- which is why I discounted his theory and waved the far-infared carrot.

[MikeM]

Interesting conversation.

The "leaks" is a thought, but the reduction in nitrate is so dramatic that the leaks must be more like a puncture. Then, there is the smell... the organic odor notable near any shower, aeration point. It may be that chemically only a very small amount of volatization can occur, but does this consider the frequency of atmospheric exposure in a TT or other super-aeration schemes?

[JasPR]

That is true Mike. I always bring up the odor at a koi show on Sunday morning as a living example of one stage of nitrogen leaking- ammonia. As you know, the smell can be quite strong and that is only with aggressive aeration. Is it only 2% of the actual TAN we are smelling?
The point of the observation is to say, if you start out with less ammonia, and as a result ,will have less nitrIte, then you will naturally have less nitrAte. if you leak several species of nitrogen along the way, you have significant change in NitrAte at the end.
JR

[MikeM]

I've spent way too much time reviewing literature on ammonia today. I've not come across a study that fits koi pond dynamics. However, I have come across enough to believe there is reason to believe volatilization is potentially significant. Unionized ammonia... the ammonia that is deadly to fish ... is said to be relatively volatile. The pH of the water is a major factor. At a pH above 8.0, unionized ammonia volatilizes rather readily. Below pH 7.0 volatilization is practically nil. However, I have not been able to find materials giving data for a rate of volatilization.

I have come across some studies involving soil applications. D.C. Whitehead and N. Raistrick have an article in the July 1991 issue of the journal Biology And Fertility of Soils in which simulated livestock urine was applied to soils. At a temperature of 20C, 38% of total nitrogen volatilized when there was a continuous flow of air. They found that the water content of the soil and humidity had little effect on volatilization.

In Aquaculture CRSP 22d Annual Technical Report, 2005, there is an article entitled "Co-Culture of Lotus and Hybrid Catfish To Recycle Waste From Intensive Feeding" the authors found that they could not account for up to 49% of total nitrogen. Their thought was that it had entered the atmosphere either through volatilization of ammonia or denitrification in the submerged soils.

Lot more to read, but my brain can take only so much in a day.

[JasPR]

I'm familiar with the dynamics of volitatilization of ammonia from soil. If you pick up a college microbiology text book there is usually a reference to this fact. One such reference reads " Because ammonia is volatile, some loss can occur from soils by vaporization, and major looses of ammonia to the atmosphere occur in areas of dense animal populations such as cattle feedlots. On a global basis, 15% of nitrogen is released to the atmosphere"
- JR