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Discussion Starter #1
I am wondering which will process ammonia faster. Plants or bacteria? That is probably an oversimplified, too much of a black and white question as I suspect the plant type plays a role.
 

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Plant type definitely does. If you have fast growing plants; wisteria, sprite, duckweed, hornwort, etc., then those will process ammonia quicker than the BB will. And then on the other side, BB will process ammonia quicker if you're only keeping slow growing plants like Java Fern and Anubias. Those plants are likely to still keep the tank nice from extra ammonia if say the cycle crashes, but not as safe as it would be if you had the fast growing plants IIRC. That's sort of an assumption....but makes sense, right? lol
 

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Discussion Starter #3
Yes. That does make sense.

It occurred to me that lighting will have an impact here as well. The BB aren't light dependent like plants are. So if the plants aren't getting enough light, that also slows their ability to consume ammonia.

So that would also have to mean that if plants aren't getting the nutrients they need, that will also affect their ammonia consumption. Does that sound right? :)

What a wonderfully intricate balance to understand, create and maintain :)
 

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I'm actually really enjoying our conversation!

Okay, so if we have to take everything into consideration then we have to look at not only the lighting, the co2 content, the o2 content but the stocking as I said in the PM I just sent. The more fish you have, the more they respire and create co2 for the plants to soak up. So if you don't have enough fish to feed your plants along with not adequate lighting and possible CO2 loss through surface agitation, then expect your plants not to do as well. I would expect though that since ammonia is part of a plant's "diet", you could say, that those factors wouldn't inhibit the consumption of the ammonia still. It's limited by what it actually in the tank of course but I would think that they would still soak it up at the same rate regardless of anything else.

At least, that's my theory on it.
 

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Discussion Starter #5 (Edited)
I am as well. Major light bulbs coming on :)

Nutrients perhaps. Need to do some more research on that one. Stocking, of course, makes perfect sense. "DING"

Lighting, though, I should think would have a significant impact. I read somewhere that lighting, the primary element in photosynthesis, has a direct impact on the plants ability to process nutrients. The less light, the slower the photosynthesis, the slower processing of nutrients. I cannot say one way or the other about ammonia absorption under differing lighting conditions; however, if a plants metabolism slows with less light, it makes sense that it's feeding slows as well.

That begs the question, at night, with no light, does a plant still absorb ammonia? I would think not as there is no photosynthesis going on. The plant is more or less dormant. Is that right?
 

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That makes sense!

I would assume so, not exactly sure how you could test for that though. Maybe have a small tank with a fish in it, like 1 gallon with some floating plants. Test for ammonia during noon and then again at midnight or right before lights come on since that's probably when it would be built up the most. So before lights come on and right before they go off would probably be the best time to try that. I can actually do that since I have that kind of situation with my pairs being conditioned! Except they're only getting ambient light...darn, maybe I'll move one of my lights to try it for a few days and see what comes of it!
 

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Discussion Starter #7
I can test this in the tank I am currently setting up. Have to think... it..... t... h...r...o...u...g...h.

Yup. My brain is slowing down from sleep deprivation. I'll revisit this a little later or tomorrow. I am getting alot out of these discussions. Funny how one question can start to bring it all together :)
 

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I'm in total agreeance! See you when you wake up! :-D
 

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Discussion Starter #9 (Edited)
Woof. Long sleep. Feeling a bit more refreshed so let's see if I understand this. As this is important for me to understand, I invite anyone who reads to comment, clarifying anything off or missed.

We are talking about an eco-system where plants and bacteria are both consuming ammonia and CO2. With the plants, the ammonia and nutrients feed the plants (there's more I know. Keeping it simple), the light provides the energy source for plants to photosynthesize and absorb nutrients (if that's in fact a word), and the CO2 provides the fuel for the plants to breakdown the nutrients absorbed from the water and substrate during photosynthesis which in turn enables them to grow.

Fish and atmospheric exchange provide the CO2, Ammonia comes principally from the fish (other sources as well organic breakdown), and nutrients come from the water and substrate.

Plants and certain bacteria compete for the ammonia and CO2 in the water. Under ideal circumstances in the tank, assuming plants are operating at peak efficiency, the plants absorb the ammonia faster than the bacteria. A balance establishes between the two where plants get what they need, and bacteria colonies grows only to a size sustainable by the amount of ammonia and CO2 available to them. (what the plants do not absorb or require). The more mature and healthy the plants, the less ammonia and CO2 is available to the bacteria, the smaller the bacterial colony. The plants have the advantage here.

Ok. Assuming all of that is reasonably correct, I'll return to the original topic, nitrogen deficiency.

As ammonia comes principally from the stocking level in the tank, the lighter the stocking, the less ammonia is available to both plants and bacteria. A limiting factor for the growth of each. As such, in the instance where the plants require more than is available given the balance of consumption between plant and bacteria, the growth could slow or stunt, which could manifest as a nitrogen deficiency in the plant.

Lighting levels will affect plants but not bacteria. If lighting levels are sufficient for the plants (assuming all else is equal) the overall energy to photosynthesize is optimal for absorption and processing ammonia, CO2 and nutrients. If lighting is insufficient, photosynthesis will slow, reducing the absorption rate of each, slowing growth. In extreme instances, the bacteria could gain the advantage in consuming and using each, stunting plant growth which could show as signs of nitrogen deficiency, perhaps CO2 deficiency as well.

CO2 levels in the water are affected by both plants and and bacterial consumption, CO2 production by stocking levels, and atmospheric exchange. Under ideal circumstance, the availability of CO2 is in a balance where plants and bacteria get the fuel they need to process nutrients; however, if, as a result of light stocking and/or too much atmospheric dissipation, CO2 is low, plant and bacterial activity growth rate slow as nutrients are processed at a slower rate. In the instance where certain plants require more CO2 than is available for processing nutrients, once again plant growth could stunt, showing in this instance a CO2 deficiency. And in this instance, fuel is insufficient, processing of ammonia could slow to the point where a nitrogen deficiency is also indicated.

Finally, nutrients other than ammonia. This is the area I will likely oversimplify the most. That being said, nutrients available keep the plant healthy, enabling the continued growth of the plant, which in turn influences the ammonia and CO2 consumption rate as well as the photosynthesis of the plant. The larger the plant gets, the more of each it will require. Insufficient nutrients will slow and I assume can potentially stop the plant's growth altogether as it will only grow to the amount of the nutrient required that is least available (I think I said that right). The deficiency for that item will show first, but in extreme cases, where the plant needs much more of that item than is available, then ammonia and CO2 could slow to the point where a nitrogen and/or CO2 deficiency could manifest.

So when trying to diagnose what is going on, knowing the plant's requirements for CO2, lighting, and particular nutrients, possible areas of CO2 over dissipation, and stocking levels in the tank. A bacterial bloom or imbalance somewhere should be considered, as should any algae imbalance that may appear in the tank.

There you have it. A bit lengthy I know, and again I invite anyone to comment for clarification or correct anything I have missed.
 

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Holy wall of text, Batman! hahah!

From what I understand, you've hit this nail on its head!

I just came across a very interesting thread that will actually ruin our theories >.< It's on a different forum and I don't think I can copy and paste the whole thing so I'll send it to you in PM form!
 

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Discussion Starter #11 (Edited)
lol... I read through the entire thread about NO3 vs. NH4 uptake by plants. Though interesting, I am not convinced of it's significance to or impact on a planted aquarium.

One reason is that Diane Walstad spends maybe 1 or 2 sentences in her book on the topic, and from Tom Barr's comment at the end of the thread. Besides that, even if plants are absorbing NH4 instead of NO3, they still compete with bacteria for the NH4, so if my reasoning above is accurate, then signs of nitrogen deficiency under all mentioned conditions would still apply.

Another point there (I am being knit picky with that debate) is plants have water parameters they prefer just like fish. So plants have probably evolved so that their requirements for nitrogen, just NH4 for the sake of this reasoning, will be met by the amount of NH4 that would be available within those parameters. So again, when seeing sings of this deficiency, the points above for seeking out the source of the problem would still apply.

I will make note of, though, that Seachem Nitrogen puts NH4 into the water instead of NO3. So NH4 is probably important for plants. Even still, under the right conditions, it wouldn't be needed. Nice to know, though, that dosing it won't harm the fish.

I did, though, find the comment about CO2 management being far more important than NH4/NO3 management. I am curious about what's involved in managing it. It also changed my view a bit on the use of CO2 injection, or Excel in a low tech tank.
 

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My thing about that was the plants prefer to soak up NO3 rather than NH4 because it is easier to break down, then after they'll go for the NH4 and NH3 depending on the pH of the tank. So that means that the BB most likely eat up the ammonia before the plants even get to it. Of course I have no proof there but I think it makes sense in my head.
 

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Discussion Starter #13 (Edited)
I may have gotten the designations backwards. I meant ammonium for NH4 and Ammonia for NO3. And Seachem Nitrogen puts ammonium in the water, which they say is plant preferred.

And I agree about the bacteria may be getting the ammonia before the plants get to it. So the question there becomes again, does it really matter?

I'm actually surprised no one else has offered an opinion here. I find it hard to believe I could have gotten this reasonably right the first time :)
 

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Ammonium is NH4
Ammonia is NH3
and Nitrates are NO3

lol, well it made sense to me at first too and I really thought we were on to something, we still are but it's just taken a slight detour is all ^_^ I think it's starting to click but I'd have to really write it all out for myself to have it truly click but I'll do that on my own since I'd basically just be copying what you said XD
 

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Discussion Starter #15
I did get that right then. I'm amazed since I repeated chemistry in college before I squeeked by

lol... I find that I have to write things out myself, then bounce it off others, for it to fall into place :)
 

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Yup! Same here! And then my boss gets angry at me when I repeat what he said--I'm just trying to make sure I've got it right!! lol oh well
 

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Yeah....I've avoided chemistry and biology like the plague here in college. I'm glad I took that Aqua Culture class though!
 

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I am pretty sure that the plants are grabbing ammonia better than BB. I cycled a tank with plants (water sprite and others) and for more than two months I did not detect any NH4 (ammonia in acid pH), NH3, NO2 or NO3. The nitrite or the nitrates would have been the work of bacteria. It was a 75G stocked with 124 angelfish juveniles. Water sprite was growing inches every day, half of it was removed on a weekly basis. The plant growth slowed down a lot once the BB established. I did not inject CO2 but I was fertilizing with Seachem Comprehensive.
Few notes from your long post Padgett:
I am not aware of a competition between plants and BB for CO2.
CO2 is the source of carbon (don't forget that same plants can use carbonates instead). Carbon is about 50% of the plant mass such as cellulose and carbohydrates such as sugars (sap) is made of carbon and water, hence the name.
Water in equilibrium with air contains about 0.5 ppm CO2 (less in warmer water), fish can bring the level at about 3 or 4 ppm. By far, most of your CO2 (in a non injected tank) comes from decomposition of organics (fish food directly or fish poop), again the work of bacteria. In a mature tank, you can reach 10 ppm CO2 via breakdown of organics. With a good KH, your water can sustain good levels of CO2 to promote plant growth.
For a looong time I was thinking about Seachem Nitrogen containing ammonia (but also nitrates if I remember well) and I had one idea about using plain ammonia as fertilizer mixed with Prime (made by Seachem as well). I will try one day.....
 

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Discussion Starter #20 (Edited)
You're right. They don't compete for CO2, although as I understand it, they do burn CO2 as fuel for breaking down nutrients for their growth. What overall impact that has on CO2 in the system I cannot say. I do know that when CO2 levels or KH is low, their growth slows. I presume that impacts plants in the same way.

Then a simple statement of the obvious: CO2 deficiency manifest when net consumption exceeds net renewal. That, in turn, could lead to a nitrogen deficiency due to the impact that has on the plant's metabolism. An educated guess, but is that right?

So the solution would be to add more CO2 to the system. Could Excel fill that function in these circumstances? I presume nitrogen dosing may not be necessary under these circumstances, as when the plants are getting more CO2, they will consume more nitrogen once again.
 
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