Water chemistry question

[bsfman]

My question is this:

Is it a one to one to one ratio of ammonia converted to nitrite to nitrate, or do differing concentrations of nitrite and nitrate result from a fixed amount of ammonia in beginning the cycle?

The reason I ask is this - my well water typically contains 4 (or maybe slightly more) ppm ammonia. I've been cycling my new system without adding fish or any new water for just 4 days now, relying on the ammonia in the well water to kick off the cycle. I did add some old media and sludge drained from my other systems' biofilters to jump start the nitrification cycle. The system is now showing just a trace (less than 0.25ppm ammonia, zero nitrites, and between 5 and 10 ppm nitrates. Water pH is 8.3. Last night my testing showed 2ppm ammonia and barely a trace of nitrites. I tested for ammonia and nitrites daily, but other than an initial test for nitrates (results 0.0) I have not tested for nitrates until the ammonia drop results this morning. I never saw any sort of spike in nitrites other than the less than 0.25 ppm last night - perhaps there was sufficient bacteria from the old media to convert the nitrites as they developed? I'm a bit puzzled why the nitrate concentration now reads higher than the initial ammonia concentration - hence my original question.

Thanks!

[urbanfarmer]

It depends, a ratio of what?

If you're talking molar ratio, then yes. 1 mol of ammonia turns into 1 mol of nitrite turns into 1 mol of nitrate...

If you're talking unit mass, such as mg, then no. 17 mg of ammonia turns into 46 mg of nitrite turns into 62 mg of nitrate.

There's another commonly used unit for that reason, and the answer is yes in that case (I won't mention it at the risk of sounding more confusing).

[bsfman]

It depends, a ratio of what?

If you're talking molar ratio, then yes. 1 mol of ammonia turns into 1 mol of nitrite turns into 1 mol of nitrate...

If you're talking unit mass, such as mg, then no. 17 mg of ammonia turns into 46 mg of nitrite turns into 62 mg of nitrate.

There's another commonly used unit for that reason, and the answer is yes.

Thanks, Urban! (I figured you'd have a good answer for me on this!)

So if I understand correctly, using the unit mass ratios, 4ppm ammonia would become 10.8ppm nitrite and eventually 14.6ppm nitrate. This tallys within API test kit accuracy at least, with what I am seeing for ammonia and nitrate. Still a bit surprised I never saw any nitrite to speak of, but my assumption is that I seeded the system with sufficient nitrobacter to continuously convert the nitrites as the nitrosomonas produced it.

I'm conducting an experiment currently. Since the nitrosomonas took the ammonia from 2ppm to zero in 12 hours overnight, I figure they will take 1ppm to zero in about 6 hours. I added sufficient humonia (gee whiz!) to bring the ammonia level back up to roughly 1ppm. Gonna monitor nitrites hourly for the next 6 hours to see if I get any sort of bump up. At the end of the experiment, if the ammonia is all converted and I haven't seen a nitrite spike, I'll know the nitrobacter ate up the nitrites as they were produced. That ought to also bring the nitrates up to 21 or 22ppm as well. (Won't be able to tell about that though since both API color charts I have show no difference in color between 10ppm and 20ppm nitrate. Grrrrr!).

Film at eleven!

[foodchain]

Wouldn't the sludge you introduced also have ammonia, nitrates, and nitrites in it?
If you only tested your well water, you have no idea of what concentrations you introduced in the sludge. Just a thought.

[bsfman]

Wouldn't the sludge you introduced also have ammonia, nitrates, and nitrites in it?
If you only tested your well water, you have no idea of what concentrations you introduced in the sludge. Just a thought.

Good question, foodchain!

The sludge came from two fully cycled systems with zero ammonia and nitrites. They run about 80ppm nitrates each. I maybe introduced 2 gallons of water containing the sludge into a 170 gallon system, so 2X80/170=less than 1ppm nitrate attributable to what I added to the system with no added ammonia or nitrite.

[urbanfarmer]

Wouldn't the sludge you introduced also have ammonia, nitrates, and nitrites in it?
If you only tested your well water, you have no idea of what concentrations you introduced in the sludge. Just a thought.

It depends. The answer can be yes or no, but typically the answer is yes. Whether the concentration is negligible or not for this scenario is unknown.

I added sufficient humonia (gee whiz!) to bring the ammonia level back up to roughly 1ppm...

The problem is humans excrete waste (well #1) mostly in the form of urea whereas fish release it mostly as ammonia (except under certain stress). Anyway, my point is: does your test kit read the urea? For example, it might have read 1 ppm ammonia/ammonium, but because 99% of the nitrogen in the "humonia" is tied up as urea and if t breaks down after you test then you could actually have added hundreds of times higher concentration than you realized.

For "testing" and trying to follow your input to output you want ONE VARIABLE. It's like an experiment. The trouble is urine has so many things in it and the many bacteria interact with it in so many ways and you could start with X and get Y concentration under Z conditions, but change Z and you have a totally different Y even though you started with the same X in both cases. Your best bet is to use store bought ammonia (clear unscented) and determine the concentration (dilute it) and go from there. Otherwise, your numbers really won't be helpful to you.

[bsfman]

The trouble is urine has so many things in it and the many bacteria interact with it in so many ways and you could start with X and get Y concentration under Z conditions, but change Z and you have a totally different Y even though you started with the same X in both cases. Your best bet is to use store bought ammonia (clear unscented) and determine the concentration (dilute it) and go from there. Otherwise, your numbers really won't be too helpful to you.

Gee whiz!

There goes my best excuse for rapid beer consumption!
Or maybe not. My duckweed pool seems to enjoy my beer drinking

[urbanfarmer]

Oh no, it's great stuff. Cheap, free, and a relief to add into the system every time! It's just too variable and unmeasurable with the tools available to use in a controlled experiment, unfortunately.

A half gallon of ammonia is $1 just about everywhere; so, not a bad investment for a researcher like you!

[stucco]

I don’t even know how far this just went over my head?

[foodchain]

How many experiments we do, that really only have one variable?
Most of mine, are more along the lines of "Hey hold my beer", and "Hey ya'll watch this".....
Needless to say....not very technical.