Understanding the EI method better...

[Bartman]

Tom

Thanks for the great website. I’ve been going through as much as possible on weekends and evenings since Greg Watson pointed me here a couple of weeks ago. If answers to my questions can be found elsewhere in the Barr Report, please just direct me there, I don’t want to take up your time answering the same question for the hundredth time…

I’m quite interested in your EI method and have started using it on my 50 gallon tank. I’m using the amounts from Greg’s EI Light listing which appear to scale up your 20 gallon EI example for larger volumes (2x in the case of the 40-60 gallon listing). I plan to use these standard values as a starting point then adjust down to my tank’s needs over time as you both suggest. It sounds as though many people have done this with success so I’m happy following in the steps of others and learning from their experiences.

Unfortunately, a shortcoming in my personality is that I need to know what I’m doing and why, even if I’m already planning to do it. (this drives my wife crazy and is probably why I’m and enginerd, I mean engineer ) So for example, I’m trying to understand what weekly NO3 concentration you are suggesting we add and the “target” concentration we are looking to build up to over time. I then want to compare that to the target range of 5-30 ppm that you list to get a better picture of where we are. Ultimately I’d like to understand what I’m doing, how it effects my tank, and how to scale up (or down) if I do other tanks in the future.

In your example you suggest adding ¼ tsp KNO3 3-4x a week (lets say 3x for convenience). The way I calculate it, over one week that would be adding :

¾ tsp KNO3 * 5cc/tsp * 2.11 gm KNO3/cc * 0.6133 gmNO3/gmKNO3 = 4.853 gm NO3

(4.853gm NO3 * 1000mg/gm) / (20 gal * 3.7854 L/gal) = 64.1 mgNO3/L = 64.1 ppm NO3

Did I do the math correct? If so, is 64ppmNO3 high since it will result in long term concentrations between 64-128ppmNO3? I would have thought 30ppm would be your target (which is about 3/8tsp per week rather than 3/4tsp) since it would put you between 30 and 60ppm which is right around the upper reaches of your guide range.


On another EI note, can you please summarize why you think the EI method works? Is the ultimate result that we end up with healthy plants that use up ammonia waste so fast that algae can’t get to it? I’m just a little confused as to why having an excess of nutrients would inhibit algae growth unless something they need is missing. In other words, if the food they need to grow is approximately the same as that need by SAMs and it’s present in excess, why doesn’t the algae grow just as well as the plants?

Thanks for you time and help figuring all this out.

 

[Tom Barr]

EI works for a few simple reasons:

1. It's easy
2. Requires no test kits(see #1)
3. It keeps folks on a simple routine(see #1)
4. It's simple(see #1)
5. It prevents anything from building up through large weekly water changes
6. It prevents anything from running out by regularly dosing 2-4x a week
7. It avoids test kit accuracy issues
8. It's very flexible
9. Keeps tank cleaner
10. I came up with it based on test kit readings and reference solutions

For modeling/estimating build up ranges, this is simple: you assume no uptake(realistically, that never occurs unless you provide no nutrients/CO2/light etc, and even then, bacteria will go after some fraction of it)

If you do weekly 50% water changes, and dose 30ppm per week of NO3, then the max amount of possible build up never quite reaches 60ppm ever.

Now 60ppm sounds high to some folks, but is it? Is it the same as NO3 build up from fish waste?

No, it's not, but many enjoy arguing with me that it is.
So I did some acute toxicity test using KNO3 with shrimp and wide range of so called sensitive fish. I had a LD 50 of shrimp only, no fish had any issues, at 160ppm NO3 for 3 days of exposure.

That's pretty darn high.
I've gone to 80 ppm of NO3 will no issues for about 5 shrimp species to date, this was maintained for about 1 week.

I'm not sure what you did with the math, adding 1/4 teaspoon 3x a week to a 20 gallon tank will never go beyond 60-63ppm NO3 if you use KNO3 and do 50% weekly water changes.

The tap might have NO3, or dosing errors etc, but these typically are not an issue unless you live where there are high NO3 is the tap(many do in the UK and Germany, Europe etc).

Now if you want more narrow ranges or less build up, you may do 75% weekly water changes or do 2x a week 50% water changes etc.

It's up to you.

Most settle on a weekly routine and larger % if they want more accuracy/less variation.

At 50% weekly water changes, this makes the math simple.
It'll never build up beyond 2x the weekly dosing.
Ever.

It's better to focus on the total you add for the week and then you can divide that into 2-3-4x a week dosing fractions. I like 3x a week because I am not here on the weekends. Many clients are not either.

So this makes it simpler to conceptualize.
The idea is very simple, but folks obsess way too much over nutrients and not enough about CO2.

Nutrient management is very easy, CO2 is much more elusive for most folks.

Regards,
Tom Barr

 

[Bartman]

I understand your list of 10 reasons (and boy do I hope to realize them!), I was asking about the biological reason why the method works. It just seems odd because it sounds like providing all the nutrients for SAMs in excess would also provide all the nutrients for algae in excess. I was wondering if the reason why algae doesn’t grow is because it needs NH4 at some point in it’s development and healthy plants use it up too quickly or something along those lines. I'm about 15 issues of the Barr report behind, but maybe I'll run across the answer in one of them. I've got to believe that you've been asked this question a million times by now...

As for the results of my (bad) math, I think I know why your teaspoon dose levels came out so high for me. I used the true density for KNO3 (2.11 g/cc), not the bulk density (~1.25 g/cc), so when I calculated the mass of KNO3 I was about 1.7 times too high. I’m guessing that the bulk density varies from lot to lot of material and from vendor to vendor so I think I’m going to work off of weights to make dosing solutions.

Your comments on NO3 concentrations are great. My concern was overdosing because many of the books I’ve read say keep NO3 under 40ppm. I knew you said you’ve gone higher, but I wasn’t sure what that ceiling was. Now I do!

 

[Tom Barr]

Why would the algae not grow all the time if you accepted that view?
How could any two different species of autotroph grow anywhere together?

Why do we have elephants and mice even though both are herbivores and eat the same resource, plant material?

Just because they both use the same raw materials does not mean they compete on the same spatial or temporal scales.

Algae(few cells) need much less than plants(Billions of cells).
Algae often have several life cycles, plants got 2 and we only use one.

Basically why doesn't Staghorn algae always grow and outcompetes say GW, or GDS, or BBA?

None are limited.

If I starved a critter, say our friend the elephant so we might starve out the mice, pest, do you think that would work?

What if I feed the elephant well and specifically the amounts it needed?

Point is, folks should focus on the plant's needs, not worry about the algae's needs.

None of these clowns that make algae claims appear to have done a lick of work showing the algae grows for a defind reason or not.

They do not know how to culture algae and induce sexual/life history stage germination. They also tend to have poor plant growing skills.

Why would someone take advice from those folks?
I didn't

Plants have a niche that is well suited to higher nutrient levels than algae.
But it needs to be stable, not varying all over.

The variation signals algae and they move in then.
Namely NH4 and CO2 variations.

Ask yourself this also: how could limiting the nutrients provide better growth for the plant? Would not non limiting nutrient allow for max growth rates?

Clearly it does and would and this can be/has been tested.
We use Hoagland's solution(He use to teach here at UC Davis BTW) as a non limiting nutrient supply for various plant test.

That rules out nutrient supply as an issue for various soil types and serves as a non limiting control to make plant growth rate comparisons with various soil types and water column dosing etc. I use the same type of thing, except without NH4 for the water column(it's all NO3 for obvious reasons).

Regards,
Tom Barr

 

[Bartman]

Why would the algae not grow all the time if you accepted that view?
How could any two different species of autotroph grow anywhere together?

Why do we have elephants and mice even though both are herbivores and eat the same resource, plant material?

Just because they both use the same raw materials does not mean they compete on the same spatial or temporal scales.

That's the very question I'm trying to work through in my mind. Why wouldn't we have algae growing all the time? We can have a region where we have a dozen or so elephants and hundreds of thousands of mice. My brain then asks the question "So why don't we end up with our large plants surrounded by millions of algae cells when we provide lots of food???"

Point is, folks should focus on the plant's needs, not worry about the algae's needs.

None of these clowns that make algae claims appear to have done a lick of work showing the algae grows for a defind reason or not.

They do not know how to culture algae and induce sexual/life history stage germination. They also tend to have poor plant growing skills.

You and I are on the same page.

I've never been comfortable with algaecides. I always felt they were poisoning everything, just poisoning the algae enough to kill it while poisoning our plants enough to only hurt them badly but not kill them.

I was intrigued by the PMDD method to control PO4 because I thought that might be the best way to starve algae while not hurting plant growth too much. The idea of providing just enough of a particular food to feed the plants while not leaving any for invasive species makes sense. The threads on the Krib were making it sound like PO4 was a food that plants could out compete algae for.

Even still, that method didn't make me feel too warm and fuzzy because I'd be knowingly limiting plant growth and I wasn't sure how difficult it would be to get good growth without regular algae breakouts.

Algae(few cells) need much less than plants(Billions of cells).
Algae often have several life cycles, plants got 2 and we only use one.

...

They do not know how to culture algae and induce sexual/life history stage germination. They also tend to have poor plant growing skills.

...

Plants have a niche that is well suited to higher nutrient levels than algae.
But it needs to be stable, not varying all over.

The variation signals algae and they move in then.
Namely NH4 and CO2 variations.

The idea of providing EVERYTHING a large multi-cellular organism (my plants) needs while leaving something out that a much smaller organism (my algae) needs makes sense as an excellent approach.

I must admit, while I do well with chemistry my biology and botany skills are sorely lacking. I have no idea what signals algae that its OK to grow, much less what signals we can use to tell algae its not good to start the next lifecycle stage without inhibiting plant growth at the same time.

So you're saying that your experience and experimental results show that CO2 and NH4 fluctuations are signals that algae use to trigger growth? That's the kind of info I've been searching for!

Let me take that thought and run with it for a bit...

So as long as we provide all the nutrients our plants need, they will grow happily. If NH4 and CO2 levels are the primary triggers (or at least two important triggers) for algae growth then as long as we keep those levels relatively constant algae will never get the signal that it's a good time to grow.

We can keep CO2 levels constant by having a reliable, constant source with a reliable, high quality diffuser. I'm guessing this is why we get algae explosions when our CO2 cylinders run out and we don't notice it for a day or two. This may also explain why DIY systems can have regular outbreaks when they start to wind down on CO2 production. (my personal experience talking here...)

Wouldn't it be great if there was some kind of probe that read CO2 levels we could use to control our CO2 regulators? Sounds like that would be a better way to control CO2 output rather than pH...

Taking it a step further, we can control NH4 levels by having lots of well growing plants around that chew up NH4 rapidly keeping it at a low level. Then we just need to have reasonable, but not tight, control on NH4 production rates. This means that we can have fish loads that would have been considered high in the past as long as we keep that load consistent (to control NH4 production rates) and don't have so many fish that it effects their health (i.e. everyone has a hiding place and enough turf to stake a claim, etc...).

Of course this assumes proper maintenance such as removing decaying plant matter and any dead or dying fish / inverts...

Do these thoughts agree with your observations?

One more thing. Is there a particular reference on algae growth you would suggest? I'd like to learn more about algae life cycles and triggers.

 

[Tom Barr]

Glad to see you got this!

You are on to the basics.

You have noted your own issues in the past.
You have seen the correlation between the models I've suggested and what you have seen.

If there are little other plants, or algae in an ecosystem, what do you think the NH4 levels would be?

Say if no other autrophic competitor was present?
What would be a good indicator that would tell a seed/spore to germinate?

How would an algal spore know if there was someone else there or not(competition or not?)?

NH4 is rapidly taken up(so no or virtually undetects), lower O2 levels also correlate(less plant growth/rotting material/stunted growth from low CO2/low nutrients etc) and lower CO2/variation in CO2.

There are various culture algae books, none are cheap and many are not that useful.

Basically, there's a great deal not known about FW algae that infest our tanks, I might be one of the better experts on the topic

Plenty of other folks know other things about the FW algae, but not those.



Regards,
Tom Barr

 

[Bartman]

What you’re saying makes sense. If there are no plants around, then NH4 and NO3 levels will be high (like when I was a kid and never did water changes ) so the algae could know that there aren’t many competitors around to compete for food.

I suppose that indicators such as low, fluctuating O2 and CO2 levels, and high NH4 levels would be a sign that there are lots of things are decaying for various reasons or that competitors may be struggling or nonexistent.

It sounds like low NH4 levels alone are not enough to discourage algae however. Many of us can have low/non-detect levels and still grow beautiful algae. I've done this off and on for the better part of a year now.

I hadn’t fully calibrated my test kit, but I did enough calibration to tell when some NH4 was present versus none. I'm pretty sure that my NH4 levels have been very low, but CO2 had been a problem until I got my pressure system last month and ferts have been a problem until last week... -> Thus the frequent comments by everyone on the BR (Barr Report) asking about CO2 levels (and the accuracy of the reading) each time someone has a problem but says they have no NH4!

On the other hand, signs of good plant growth such as low NH4 levels and good CO2 and O2 levels can act as signals to algae that it would be better off waiting until conditions are more advantageous before trying to start the next phase of development.

In nature this probably works for them because they can float down stream until they reach a better location. If they’re in a lake or pond the aquatic environment changes throughout the year and they can just wait until ideal algae conditions show up.

In our aquariums we hopefully never let the tank conditions get optimum for algae so they stay dormant waiting for their chance to ruin our weekend…

So this is probably why people who do frequent, large (or continuous) water changes rarely have algae problems. There’s a constant replenishment of CO2 and O2 (via dissolved content in the new water) plus a replenishment of nutrients to ensure proper plant growth.


Sound about right?


I should mention that I've now been on EI for about a week and a half and the algae in my tank are retreating and my swords are sending up flowers & plantlet for the first time ever!

 

[Bartman]

Forgot to mention, just picked up a CO2 drop checker for $20 on e-bay (the knock-off because the teardrop shape looked neat) and a Rhinox 2000 diffusor for $10. I'm pretty happy about the diffuser price.

My CO2 readings and addition should be even better when they show up (hopefully next week).

 

[Frolicsome_Flora]

hehe I ordered that very same item from ebay, should get it any day I hope, was a bargain at 50% retail. I have a Red Sea type one at the moment, but its a pain because the light doesnt shine through it, making it hard to tell what colour it is, even with the white check strip.

 

[Bartman]

I was about to get the Red Sea one, but once I saw the two styles of glass units I thought the extra $10-$15 was worth it. I figure that I'll save more than that in KH and pH test kits anyway...

I hadn't thought about the ease of seeing through it. That's a very good point!

 

[defdac]

If pulsing NH4 is a trigger it's wierd that Tropica uses NH4 in their new line of fertilizers - and that they claim that NH4 doesn't trigger algae growth more than NO3.

 

[Tom Barr]

Tell you what, add some and see for yourself.

If that were truly the case, why would anyone use KNO3/KH2PO4, and why would jobes sticks and other terrestrial fertilizers induce algae?

Think about it.

It's all about the dose of NH4 under a given set of conditions.
A tiny bit, say like from the fish waste, not an issue in a reasonable stocked tank.

Why cannot we just keep adding progressively more and more fish for N fertilization if that where the case as well?

I can add say 0.2ppm of NH4 without ill effects to many tanks.
But 2.0ppm?

What about sublethal effects of NH4 on fish health?
NO3 has a very high and wide range, NH4 is quite nasty.

Folks carry on about how EI suggest "high levels of pollution" for NO3 and PO4.
Yet I see nowhere near the same reaction to NH4 dosing, which has a long history of aquatic toxicology even at low levels.

We have tried NH4 dosing in our local group about 4-8 years ago for period.
No one came away believing the practical dosing of NH4 was worth the gain.

Not one person.
Will plants use it?
Yes.
Will they grow a lot better with it?
Not really as long as there's an ample supply of N from any source.
Will overdosing cause issues?

Steve, Erik, Jeff and myself all think/thought so.
I would have never been able to induce Green water without NH4 dosing(I tried, I used very high levels of NO3/PO4 etc, never was able to, still to date never have been able). Erik and myself ran into issues using NH4.

It's like playing with fire. He got algae and so did the other folks.
I'm sure Tropica is aware of it. So they add it, and then make sure is very dilute, dose makes the poison.

I am not sure why they word the NH4 issue that way, but if pressed, they would reneg I would think and certainly would hope.

Get some NH4Cl, (NH4)2 SO4 and dose yourself.
Add terrestrial fertilizers/jobes sticks
Add progressively more and more critters till you get algae
Use higher light and CO2 and non limiting concentrations for the other nutrient levels.

Then see what you think.
I have not seen anything that would suggest higher levels of NH4 is good for fish, for plants, nor is able to entirely satisfy the N needs for plants in higher light CO2 enriched systems.

Of course if you plan on adding a tiny amount relative to a dosing routine, why bother using Tropica at all?

Go get some Miracle grow for 1.99$ and make 20 gallons of comparable Tropica stuff for 100X the cost

Either way, what they say is either going to shoot themselves in the foot with DIY terrestrial ferts or the observations I've done over a few years as well as many others are wrong, but .................I doubt it

That said, another friend in the Netherlands suggested a method to add solely NH4 to tanks without algae. He had to do daily 80% water changes though
He added about 0.5-0.8ppm per day to meet the needs in a moderately low light tank.

If the CO2 is off in higher light tanks, GW will occur fairly consistently. So it's multifactorial in the algae inducement: it requires changes of CO2/NH4/light intensity/water change rioutines and perhaps other nutrients(although correlative evidence is weak there).

I also do not know how much NH4 is in the Tropica product. That's always an important issue.

Regards,
Tom Barr

 

[Tom Barr]

Tell you what, add some and see for yourself.

If that were truly the case, why would anyone use KNO3/KH2PO4, and why would jobes sticks and other terrestrial fertilizers induce algae?

Think about it.

It's all about the dose of NH4 under a given set of conditions.
A tiny bit, say like from the fish waste, not an issue in a reasonable stocked tank.

Why cannot we just keep adding progressively more and more fish for N fertilization if that where the case as well?

I can add say 0.2ppm of NH4 without ill effects to many tanks.
But 2.0ppm?

What about sublethal effects of NH4 on fish health?
NO3 has a very high and wide range, NH4 is quite nasty.

Folks carry on about how EI suggest "high levels of pollution" for NO3 and PO4.
Yet I see nowhere near the same reaction to NH4 dosing, which has a long history of aquatic toxicology even at low levels.

We have tried NH4 dosing in our local group about 4-8 years ago for period.
No one came away believing the practical dosing of NH4 was worth the gain.

Not one person.
Will plants use it?
Yes.
Will they grow a lot better with it?
Not really as long as there's an ample supply of N from any source.
Will overdosing cause issues?

Steve, Erik, Jeff and myself all think/thought so.
I would have never been able to induce Green water without NH4 dosing(I tried, I used very high levels of NO3/PO4 etc, never was able to, still to date never have been able). Erik and myself ran into issues using NH4.

It's like playing with fire. He got algae and so did the other folks.
I'm sure Tropica is aware of it. So they add it, and then make sure is very dilute, dose makes the poison.

I am not sure why they word the NH4 issue that way, but if pressed, they would reneg I would think and certainly would hope.

Get some NH4Cl, (NH4)2 SO4 and dose yourself.
Add terrestrial fertilizers/jobes sticks
Add progressively more and more critters till you get algae
Use higher light and CO2 and non limiting concentrations for the other nutrient levels.

Then see what you think.
I have not seen anything that would suggest higher levels of NH4 is good for fish, for plants, nor is able to entirely satisfy the N needs for plants in higher light CO2 enriched systems.

Of course if you plan on adding a tiny amount relative to a dosing routine, why bother using Tropica at all?

Go get some Miracle grow for 1.99$ and make 20 gallons of comparable Tropica stuff for 100X the cost

Either way, what they say is either going to shoot themselves in the foot with DIY terrestrial ferts or the observations I've done over a few years as well as many others are wrong, but .................I doubt it

That said, another friend in the Netherlands suggested a method to add solely NH4 to tanks without algae. He had to do daily 80% water changes though
He added about 0.5-0.8ppm per day to meet the needs in a moderately low light tank.

If the CO2 is off in higher light tanks, GW will occur fairly consistently. So it's multifactorial in the algae inducement: it requires changes of CO2/NH4/light intensity/water change rioutines and perhaps other nutrients(although correlative evidence is weak there).

I also do not know how much NH4 is in the Tropica product. That's always an important issue.

Defdac, if NO3 can induce algae at high levels, why don't I ever get GW using that? I mean, come on, I added 160ppm for 3 days and no algae, none at all or any species, this is under 6 watt/gallon and non limiting conditions.

But the same tank can have a NH4 dose added at 200X less and induce a nasty bloom of GW?

What do you think induces algae based on your experiences with just KNO3 alone? Do you see any algae inducement correlation with KNO3?

I never have.
Except under limiting conditions(BGA namely and secondary effects leading to algae, but never due solely to higher levels of NO3).

Folks that have seen such correlation also have not set up a proper test as they had other limitations such as CO2, or PO4, traces, poor plant growth to start with etc.

But if you rule out other external factors within reason, then you will not find any relationship from 5ppm NO3 to 150ppm. Repeat with NH4. You will not see the same effects. Note, do not test NH4 with fish, or fish you are concerned about enough not to want to lose.



Regards,
Tom Barr

 

[Frolicsome_Flora]

If pulsing NH4 is a trigger it's wierd that Tropica uses NH4 in their new line of fertilizers - and that they claim that NH4 doesn't trigger algae growth more than NO3.

I wonder if the thinking behind using NH4 in their ferts is to produce more NO3 from the nitrogen cycle.. seems damn weird though, why not just add more NO3. I also wonder if Tropica are placing sole focus on plant growth and throwing fauna health totally out of the window, which seems very irresponsable. But I guess the point is, like Tom said, how much NH4 is actually going in, but it seems to me that any amount is too much.

 

[Tom Barr]

Small amounts of NH4 to a healthy system is fine.

The key is the dose.

and also note: healthy system............

Adding more NH4 to a messed up tank is going to make it worse, not so with NO3 and PO4.

Algae are not limited by N and P in our tanks.
They are induced by excess NH4, so that's a good way to increase algae though.

Yes, some down regulation of NO3 occurs in some plants if NH4 is present, but how much NH4 is required before down regulation occurs?

Probably a fair amount based on research.
0.7-1.0ppm NH4 or so I'd say.
Those are not levels I'd ever want in my tank.

So when folks talk about NH4, they need to be specific, the devil is in the details and generalizations make for a lot of confusion and misinformation on this topic.

Give the conditions, the concentrations etc.


Regards,
Tom Barr

 

[Bartman]

I need to go back and refresh my memory, but I believe that Diana Walstad found aquatic plants will preferentially (and more rapidly) take up NH4 over NO3. Given that, I can understand the interest in using a faster/more effective N source.

One must question however, if the side effects are worth the increase in uptake rate. Just because one option has advantages over another doesn’t make it the best or safest alternative.

Since NH4 is pretty toxic one would have to be much more careful when dosing so its risky but maybe an option to an experienced aquarist. Novices are much more at risk of overdosing and would probably be better off avoiding it simply on that note. I think we all agree on this point.

Another question is “is there a safer alternative?” I work in the chemical industry and constantly ask myself that question when I design processes. I think that’s a question we should all ask ourselves regularly, especially when doing something that can effect others lives, even if its just a $0.50 neon tetra.

Even if NH4 can be used as an effective source of N, even if it’s a faster/better source, are the risks worth it? You have to consider the health of your plants AND fish when answering this question.

If there is a safer alternative that can be as effective, and over the last several years Tom and other have shown NO3 is just that, then I question why you would want to use NH4 over NO3 dosing?

Just because you can do something doesn’t mean you should do it. My wife reminds me of that regularly.


I’ll get down off my safety soapbox now because there’s another side to this story that I’m more interested in… Just how does NH4 effect algae blooms? Ultimately, I’d like to fully understand the story so I can know what to do to avoid algae blooms and what to look for as a potential cause if a bloom does occur.


Tom – in your experiments did you maintain your NH4 dosing even after the algae bloom, and if so for how long? I’m curious if uncontrolled algae growth continued even after the tank stabilized over many days/weeks.

This would provide insight into how NH4 encourages algae growth. Is there an upper limit on concentration where algae growth becomes inevitable no matter how stable other parameters are, or is it the CHANGE in NH4 levels that induce algae and once that parameter has stabilized the trigger goes away?

It sounds like both theories may be true. Did your friend in the Netherlands settle on 0.5-0.8ppm because that gave optimal growth, or did they find higher concentrations lead to algae (or both)?

Your comments also lead me to believe that your observations indicate a stable tank with other parameters well in hand can recover from an algae outbreak better/faster and one out of whack. This makes me wonder if that’s because the healthy plants can rapidly uptake the NH4 and lower the concentration below some “magic level” or just back to the point where they outcompete the algae again.

This is some interesting stuff here!!!

 

[Tom Barr]

I need to go back and refresh my memory, but I believe that Diana Walstad found aquatic plants will preferentially (and more rapidly) take up NH4 over NO3. Given that, I can understand the interest in using a faster/more effective N source.

Well, how often do you plan on having 1-2ppm of NH4 in your tank?
Below say 0.5ppm or so, plants, at least the one plant she used to justify this claim and generalize to all aquatic plants, a very dangerous assumption at best, preferred NO3, not NH4 when you apply normal aquarium conditions.

The rate of uptake is suggesting preferences.
So if you look at the graph with Elodea and NH4 vs NO3 over time, you will see once the NH4 declines to lower level, about 1.0-0.5ppm NH4, the NO3 rate kicks in.
From then on, the rate of uptake is higher for NO3 than NH4.

So it depends on what concentration you are talking about.
I do not think she looked at that graph very carefully.

It's not practical to have nor maintain 1-2ppm of NH4 in any aquarium.

One must question however, if the side effects are worth the increase in uptake rate. Just because one option has advantages over another doesn’t make it the best or safest alternative.

Since NH4 is pretty toxic one would have to be much more careful when dosing so its risky but maybe an option to an experienced aquarist. Novices are much more at risk of overdosing and would probably be better off avoiding it simply on that note. I think we all agree on this point.

Another question is “is there a safer alternative?” I work in the chemical industry and constantly ask myself that question when I design processes. I think that’s a question we should all ask ourselves regularly, especially when doing something that can effect others lives, even if its just a $0.50 neon tetra.

Even if NH4 can be used as an effective source of N, even if it’s a faster/better source, are the risks worth it? You have to consider the health of your plants AND fish when answering this question.

If there is a safer alternative that can be as effective, and over the last several years Tom and other have shown NO3 is just that, then I question why you would want to use NH4 over NO3 dosing?

Just because you can do something doesn’t mean you should do it. My wife reminds me of that regularly.


I’ll get down off my safety soapbox now because there’s another side to this story that I’m more interested in… Just how does NH4 effect algae blooms? Ultimately, I’d like to fully understand the story so I can know what to do to avoid algae blooms and what to look for as a potential cause if a bloom does occur.


Tom – in your experiments did you maintain your NH4 dosing even after the algae bloom, and if so for how long? I’m curious if uncontrolled algae growth continued even after the tank stabilized over many days/weeks.

This would provide insight into how NH4 encourages algae growth. Is there an upper limit on concentration where algae growth becomes inevitable no matter how stable other parameters are, or is it the CHANGE in NH4 levels that induce algae and once that parameter has stabilized the trigger goes away?

It sounds like both theories may be true. Did your friend in the Netherlands settle on 0.5-0.8ppm because that gave optimal growth, or did they find higher concentrations lead to algae (or both)?

Your comments also lead me to believe that your observations indicate a stable tank with other parameters well in hand can recover from an algae outbreak better/faster and one out of whack. This makes me wonder if that’s because the healthy plants can rapidly uptake the NH4 and lower the concentration below some “magic level” or just back to the point where they outcompete the algae again.

This is some interesting stuff here!!!

Your last paragraph shows your understanding best.
This linkage of NH4 to other causes is critical I would suspect.
If the production of NH4 is going along and being balanced/removed by vigorous plant growth, what would happen if the plants slowed their growth say 10x less?
If you stop adding CO2 all f a sudden, that will give you that rate decline and will also give you algae in most tanks. the higher the light, the more likely you will get algae outbreaks.

What you gain from NH4 vs NO3 is nothing I've been able to see personally, at least in the water column. Given that and the toxicity issues with NH4, why bother?

There is just not the research and information available out there to answer your questions, I think many that research has solved every issue and looked into everything, not hardly. My test are rather informal pilot studies.

Few folks are interested in inducement of algae spore germination in a planted tank. NH$ makes a good easy bio available signal for algae spores. Plants have no need because they are billion's of cells and have far more resources and methods to deal with their environment. If you are a single cell spore, you have to make sure you make it to adulthood and release the next generation.

It's a lot like saying the grass below the forested floor competes with the Trees.
Algae and plants are in different ecological niches and really do not compete directly. Light would be about the only thing I'd say and the plants win out there.

Otherwise we'd not have aquatic plants
We'd have one species of algae only.

But many do not think beyond their own statements

Regards,
Tom Barr

 

[vidiots]

I hadn’t fully calibrated my test kit, but I did enough calibration to tell when some NH4 was present versus none. I'm pretty sure that my NH4 levels have been very low, but CO2 had been a problem until I got my pressure system last month and ferts have been a problem until last week... -> Thus the frequent comments by everyone on the BR (Barr Report) asking about CO2 levels (and the accuracy of the reading) each time someone has a problem but says they have no NH4!

The part of this that was the hardest for me to get my mind around was the why test kit measurements are not always as useful as one might think, even calibrated ones. This is because they only tell you the amount in lingering in the tank, and not how much is being produced or used up. Meaning you could have a very large amount of NH4 being produced and be available to used up by bacteria, plants and algae and still measure low on a NH4 test kit. You could also have a very small amount being produced that is not being used up by bacteria, plants, and algae so it builds up and gives a high reading on the test kit.

It is my understanding that this method works by limiting the amount of NH4 that is available by suggesting light fish loads and also water changing away the NH4, while still providing all the nutrients needed for the plants and thus reducing the trigger for algae.

My understanding of this could be flawed, but I too say that I have had much better success with plants since I gave this method a try than I ever did before.

Makes me feel good whenever I see I'm not alone in always questioning why things work.

I have also played with culturing green water and found that using ammonia as a trigger was extremely helpful in causing the bloom. Found that liquid Miracle grow (contains ammonia), water, and light was nearly the perfect reciepe to cause and grow green water.

 

[defdac]

Makes me feel good whenever I see I'm not alone in always questioning why things work.

Ditto! =) I love posts by aquarists taking their time to test around and think about things. EI is bad that way since it's a one size fits all kindof method. That said I wouldn't have had a nice planted tank without it.

I started testing what Tom said when he started writing at APD years ago because 1) all other aquarists just said "Do what I do because it have worked a hundred years" and 2) he could explain what was actually going on and the reasons why things worked or not.

I miss the small "hobby science"-test setups folks were doing prior though. They might not be that useful and they even might start new myths, but then again that is a fun way of learning things. Doing a method just because a great name like Tom says so is much less fun. Especially when the argument often is "because I have had a thousand tanks this way all looking great". I'd rather have a theory and a test setup than a finished "untouchable" method.

 

[Tom Barr]

T
I have also played with culturing green water and found that using ammonia as a trigger was extremely helpful in causing the bloom. Found that liquid Miracle grow (contains ammonia), water, and light was nearly the perfect reciepe to cause and grow green water.

So have you tried this using KNO3/KH2PO4?
Have you been able to culture GW?

I have not.
I've added everything minus NH4 and urea which rapidly turns to NH4 in water/aqueous solutions.

I have not done much with urea alone though.
Many folks seem to think urea last longer as a source of reduced N, it terrestrial systems, that is true generally, but not in FW/SW.


Regards,
Tom Barr