[plantbrain]

Originally Posted by gmccreedy

Now Tom,
Through your explanations here, I have read and cleared up in my mind alot of things I never really knew...however, question for you:

You are asking a very good, but sometimes complicated question.
Not everyone gets it either. And there are trade offs, thus that is what one should focus on.

Those trade offs are personal choice, thus not one that is a clear one shot formula.

What level of error, or results that you accept is also a choice etc.
Some might only want 5% error, others might have little issue with 10%.
And so on.

If Nutrients dosed to the water column are not "bad", then why reccomend WC's in the EI dosing method?

They are bad if you allow them to get to toxic levels.
So the question becomes: what concentrations are "bad"? Where do you see the effects on animals or plants?

This becomes not so general a question.
We have focused the question more precisely.

So for NO3:
For example, 160 ppm of NO3 derived from KNO3 dosing killed 50% of the Amano shrimp after 3 days exposure. No FW South American wild fish where lost during this exposure treatment.

Other parameters(other than K+ which we assume is not likely to cause any issues for fish or shrimp) where tested in non limiting ranges during the 3 days. The tank was stable prior as well, thus we could call it a control (as well as after except for the shrimp_).

Note, this does not prove that 160ppm kills shrimp, but it does show that this level is perhaps toxic, and that shrimp would appear more sensitive than fish where no effects where observed(short or long term).

This is a lot more informative that "bad".
That tells you nothing is useless information.

For all the love of test and expounding on the virtues of testing, clearly if you cannot answer or set up the most basic biological questions that define your own argument/s, what the heck?
So I tend to focus on things I can test and measure.

And then I have something other than belief and meaningless marketing style words and phrases. I'm not a salesman. I do not write nice poems. It's cute etc, but hardly the meat on the bone.

EI grew out of testing + WC's.
Same for Amano.

He chose to add heavy sediment ferts + water column ferts(light) + water changes to reduce any unknown variables.

I chose to use water changes to remove the need for testing and the assumptions that they involve(which are many and many folks hate testing, or simply do not do it even if they agree they should).

This simply allowed me to add dry ferts easily(making solutions was an issue for folks, they thought it was complicated etc) and not need to test.

I have other reasons: ever try pruning in a full deep tank 24"?
Ever try working on the lower parts of tank when it's full of water?
It's much easier to work on tanks in various displays when you have less water.

It also keeps the muck down when replanting, gardening etc.
You cannot over do water changes, they are simply a tool that we can easily use and they are fast, involve no chemistry or unknowns, nor test kits.
For most folks, this is simply much easier and more practical.

I can automate and semi automate a water change, you cannot do this well with testing. I can also drain and refill a tank in a few minutes, and while the tank is refilling, I can clean and prune, stock ferts, change CO2 tank etc, so it's not wasted time at all.

Those are the "meat and taters" of aquatic plant gardening, not testing water parameters.

ADA As imparts a fair amount of tannins to your water, it' gives a yellow hue and this coloration is variable batch to batch. ADA suggest adding Carbon and I know Amano has used Zeolite in the past/present.

EI need not be 50% weekly, it can be 50% 2x a week, or 80% weekly, or 30% weekly etc.

Your error term(with 50%, it's 2x whatever rate of ferts you add assuming the tap is zero), will change to larger values as you decrease the %, and increase as you increase the % WC.

If you increase the frequency, you decrease the error as well and so on.

Now if you maintain a nice stable tank(a key part of any test) and impose a treatment, say no water changes for 4 weeks, and make sure the CO2 and such are in good shape, there's no reason why you cannot go 2-4 weeks, especially if you tweak and observe plants.

You can get a feel, especially after a few years in the hobby, for this.
But.........not everyone can do this and there are times even when the bets person gets too confident.

However, few new folks are going to be able to do this well.
So EI allows a simple easy method to re set the tank without a test kit.

I use to have narrower ranges and suggested test kits about 11 years ago, you can see that article on my site or on SFBAAPS etc.

EI was just a simpler method, but had trade offs, but those are fine with most folks.

If you wanted even more accuracy or precision, there's no reason you can not put EI into a bottle of water and divide by 7.

But that's PMDD+PO4.

Which scared many folks.

And that's all PPS is, but they rationalize more use of test kits to avoid water changes, that is the only difference btw PPS and PMDD+PO4. One suggest water changes still, the other does not.

EI, ADA, Tropica, PPS etc, we all add the same ferts.
Different amounts etc, but they still provide enough nutrients.
So they really are not that different.

ADA is very lean in the water column overall.
But they make up for it using low light most of the day and rich sediments.

EI and PMDD+PO4 and PPS all came at things more from a Water column approach.

However, they do work well together.
They complement eachother, not exclude.

Some methods, for exampl PPS Pro dose lean and do not reccomend WC's at all.

But you can still use it and do water changes.
This works fine as long as you do not go too lean, but here's the problem:

Would you if you where going to study say CO2 demand in aquatic plants, want to teeter on the min amounts and potentially have limiting conditions that would influence and confound your results? Or would you prefer to test with non limiting amounts?

You can see clearly the issue in interpreting such data and the error that it injects.

It is better to come at this question from the other end, go with a non limiting amount, and slowly reduce the ppm's /dosing down until you see a negative response in growth etc.

Stunted plants, whether from CO2, PO4, NO3 etc do not respond well and are poor indicators of treatments.

Ask any researcher in plants.
This is incredibly basic research methods.

So how did I come to this idea for light + these other ppm's?
I used a lot of luight, so much that it was unlikely anyone would have more.

At that intensity, the CO2, the ppms of PO4 and NO3 all would be at their max rates.

At the lower end, it's extremely light dependent, you have much less error.
And as aquarist go, we have lots of errors.
We are human.

If you reduce the EI dosing down, or rather PMDD+PO4 in this case to make things more comparable, slowly, or if you raise from an extremely lean PPS level up, they should arrive at the same points.

You could also argue that you could add lots of PPS and or extremely lean PMMD+PO4 and do the reverse treatment to get to that just "enough point".

For all the carrying on Edward did, he never acknowledge this point.
The only real thing he suggested was not doing water changes over very long time frames using test kits, which of course, if the test are correct and the methods used, should be okay.

And I've never said PPS would NOT work, however, I do have issue with the comments made about EI, I'm also not a one trick pony, I do suggest zero water changes with non CO2 methods, whether they are soil based or not.
The reason there is one based on rate. The growth rates are very slow and as such, no water changes is needed to remove unknowns or build up, nor are any limitations that intense since growth is so slow.

You can use less light and reduce the water changes and dosing for EI or PPS to next to nothing.

If you also use a nutrient rich sediment, say ADA AS or soil/clay loam etc, then you can avoid most all water column dosing, perhaps even K+ and traces.

Some folks in Brazil a few year back did just that, they had no access to KNO3 etc, so they use worm castings boiled, than a cap or sand, they added high light and traces and some K+(I think).

They had excellent results.
Many folks have used soil based tanks + CO2.

All with varying degrees of success.
But if you pre mineralize the soil, then you have far less error and much higher success.

This advice was from myself, with an understanding of N cycle and NH4 and O2.

The same can be done ahead of time with ADA AS.
Eg the Dry start method.

By the flooding time, the NH4 is already => NO2=> NO3 and you still have the NH4 inside the grains, just not in the water column.

(quote)
However, even with the lean dosing, nutrients will still be in excess at some point if the plants do not uptake all that is dosed. Yet, they claim no WC's.
(/quote)

Yes, there's nothing wrong with that either. What levels are problematic?
At what point does K+ cause issues?
Or PO4?
Or NO3?

I know, because I've tested this, which is why I agree.
However, the PPS folks have not bothered to test this in any real study to see.
"Yes, it works and I have no issues."
That's about all they can say, they cannot say at what point and over what range it really works or not.

It does work better if you use less light BTW, every method does.
you can do fewer water changes, run les slight etc and add less CO2.

And you finally end up with a non CO2 tank method.

Understand?
I appear to be the only person has been able to rationalize each method and tie them all together. But then again, I better be able to, I do study this stuff

EI enforces a strict regiment of WC's. So whats the catch here? What are you not getting accross?

This is not argumentative at all... I am merely probing your knowledge and experience to get a better handle on your logic.

Thanks in advance!

No, I can tell honest questions, those are extremely welcomed!
But many confuse such questions, as well as my responses with personal muckery.

These are precisely the types of questions a wise aquarist would ask.

EI does not impose strict water changes, it only provides a theory for providing a working range that the user defines, not me, not Amano etc.
50% is a simple working example.

I clearly state and have said this for decades now, it's not written in stone, you can tweak it for various conditions and goals that you might have.

Amano's advice is no different nor is Jeff or David's nor Karen's nor Claus etc.

Anyone should be able to tell the effects of large water change afterwards on their tank. Do one early in the morning, about 1 hour after the lights come on, dose EI right after.

Later at night, check the tank.
Then check the O2 and pearling.

Next, try the same check the next day, and the day after and so on, till the next water change.

Generally it's a CO2 and removal of periphyton from the flushing.
CO2 is the largest player in most folk's tanks.

That is where you will see the largest effect/s.
On algae, on growth, on the downstream nutrients, and so on.

Yet it's the biggest issue for most and measurement is Extremely difficult vs NO3, PO4 etc.

So if you are big on testing and stability, I'd really focus there.
Also, focus on maintaining the same plant biomass stability via pruning often, cleaning filters, same circulation patterns/flow rates etc, this will provide the stability far more than nutrients.

Why?

Plants define the system, not nutrients or algae, unless you mess up the plant growth rates.

Regards,
Tom Barr