Re: [APD] Substrates and testing

[Thomas Barr <tcbiii at yahoo_com>]

>Seriously, I think that when Tom Barr tests something like
>Aquasoil  
>and pronounces that it grows at least some plants better than
>other  
>substrates, it almost certainly does.

Well, I'm not suggesting anyone take **my personal word** for
it, I'm not much of faith based aquaristics:)
Never have been either.

I suggest methods and I suggest folks try it out and leave their
own conclusions to do the deciding. Most are way too lazy, but
then a select few like to argue and waste their time with
semantics rather than answering the damn question.

I'm never sure what the heck folks are thinking that 
Science is "proof", "absolute" or "certain".
It might be "very likely" and talks often in terms of
probability......likelyhoods, p values, but there is no absolute
"truth" in science. While such uncertainty many find
disconcerting, science does after all, work really really well.
Gravity is, after all, just a theory..... 

I often suggest they look in specific areas before ruling
something out. Being careful is wise.
Not being careful brought many wonderful myths.

Poor assumptions get  folks into trouble, simply being
reasonable and looking under every stone is what needs to be
done. I suggest such places to look and consider.
I do not hide off in some lab and come out and tell folks things
without any support or types of test that will answer the
questions at hand, I freely tell folks what I do and how I have
done it, what the question I hoped to answer was etc.
"Does this logic and test seem reasonable? Why or why not? How
can it be improved?" and so on.......

If anyone wants to critque it, knock yourself out and get off
your duff, start doing the test and research, background reading
etc. 

I have never asked anyone ever to accept what I say based on
faith. Rather, I do ask folks to THINK, set up a test that will
hopefully answer their question, then test it themselves and
then think about what might to the case or not.

Scott, I know you meant no disrespect and certainly none is
taken. For the record, I've posted some soil test with the
criteria you were seeking, I recently did for 5 soil types in CA
on my site as a MS word doc.

Read it and see if you think if I know what I'm doing here. I
can also email it to you if you have issues with it.

You can also read my arguments for setting up a test to
determine if a substrate might have added benefits if you dose
the water column under non limiting levels, for plain
sand(something I used for 10 years doing good water column
dosing), vs say Flourite(another substrate I've used about 10
years) vs ADA Aqua soil vs plain old well soaked soil(something
that I've used for longer than 10 years and have about 1000
replicates at the lab with 4 plant species for herbicide
testing, I added several(4) ADA AS soil smaples in there).
At the lab the water is flow through, so there's no influence on
the water column which is nearly pure other than
Mg/SO4/Ca/CO2/bicarb. ADA AS influences the softness(KH namely),
so whether it's that vs the nutrient content is an issue many
overlook very often! At least rule that out prior to making a
stink with me over it.
The other issue is having enough time and tanks to do enough
replicates, this reduces error a great deal. One tank is a weak
support, so testing a few more times on various wide ranging
tanks is a wise idea first.

If you, or Tropica, or anyone else would like to suggest a
better solution and is willing to do the work, hey, do not mind
me, pony up.

I'd be interested in reading what you have done and your
reasoning. I'm just as much a poor schlep trying figure things
out with my feeble mind as the next guy. Trying to stay ahead of
various assumptions.

There's only so much we can do with the water column, I've
acknowledge that 10 years ago.

There are some good research papers out there on various
nutrient issues such as water column vs sediments, see
Cedergreen and Madsen, 2001.

It's an excellent paper on partioning and nutrient sources.
It only deals with 4 species though. Not 300. 
Now if you can do some homework and read up on the background
research as well, set up a test that makes sense, rules out the
issues, then argue with me about it, I'm game.

But no one really tkes me up on such fun plant debates any
longer except in the academic realm.

Hanging out with Ole and Troels was fun(Troels looked "normal
sized" against a 100 meter Redwood), but I think we hardly spoke
of aquatic plants in tanks for 2.5 days after the convention,
and what we did, was "entirely in agreement".....sediments,
water column etc. 

My point is that if you think about it, do the test, listen to
folks that have done such test, read what's been done prior,
you'll be able to learn and solve much more than mere
observation alone.

If you are not willing to do the work, read some background and
answer things, then you should not be willing to argue about it.
You are unprepared. It's like coming to class and wanting to
argue about homework when you have not even done it.
It's not personal either, just the best way to answer questions
without 100K$ of grant money for this lowly hobby.

If the work makes sense, better than an alternative hypothesis,
then by all means, go with it. It does not mean it's right, but
you'll have to be more creative with the hypothesis and null.

So far, I've not seen anyone suggesting any hypothesis and not
one dang test. It's been some time since anyone has. Tropica is
about the only one and Troels and Ole are generally the ones
doing that these days. We have gotten many things right over the
years, more than most and told folks about it. 

Everyone knows I'm critical of the ADA line and marketing
information, so it would take a lot of convincing as well as
SeaChem's line to change my mind.

Folks that use ADA are already sold, it's preaching to the
choir. They tend to be experienced folks already and willing to
pay more for such products, or have enough $ that cost does not
matter. There is little grey area. So I tested and did some
practical test to see if what I could see could be generalized
and what specific part is improving plant growth, then set about
a test to show that.
Now if the average aqaurist can see the improvement in growth, I
figure there's something to it that's significant if I rule out
other potential causes.
Same deal with dosing PO4 or more CO2, or algae inducement etc.
  
While not mandatory(I've yet to suggest this), some marketed
substrates can certainly get you one step closer to easier
management and better growth. Each step helps the hobbyists get
that much closer to being able to produce a nice scape/garden
etc.

Life today is much easier than when I first started posting.

Better growth and managed growth are two different things BTW,
some seem to confuse those all too much and blame nutrients
and/or their location rather than lighting and CO2, the two much
more basal and obvious parameters.

Hopefully more will do basic test and think about how to rule
out the other confounding factors, like assuming that the water
is non limiting/stable etc and then looking at plant growth in
specific species under a wide variety of substrate types.

It's much easier to set up such test than many believe.
And in most cases, if the result is really particularly
significant, you can see it without having to do a lot of
measurements, it either works well or it doesn't.

Main things are the assumptions and being careful to maintain
the conditions during the test.

After all, the substrates are not going anywhere, nor the
water/lighting etc, so water column and CO2 is all that's needed
to focus on while you observe plant growth.
Now go get testing and/or add more to a better designed test
that has some alternative I've overlooked(A very definite
likelyhood:-).

Regards, 
Tom Barr

www.BarrReport.com


 
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