[APD] Swords and ferts/CO2

[Thomas Barr <tcbiii at yahoo_com>]

> Date: Thu, 10 Aug 2006 13:09:05 -0600 (MDT)
> From: gbooth at frii_com

> Sword plants of all shapes and sizes LOVE high tech tanks. 
> Even plants
> that are supposed to be dwarfs don't stay small very long -
> ask Neil
> Frank.  We have some of his "dwarf" hybrids (perhaps the ones
> discussed
> recently) and we are continually ripping off 30" leaves from
> the plants in
> our 100 gallon Dupla-style tanks (the tanks are 22" tall with
> 3" of quartz
> gravel with laterite and substrate heating coils).
> 
> "May", as in "may not grow", is the operative word here. At
> least you
> hedged your bet. I would hedge my bet by saying they "may"
> grow too $ at ##&
> well, regardless of what you think they prefer.
> 
> G

Well, the "on topic part about plants, swords in particular" is
dead on................

And as far as some folks claiming swords prefer this or that or
that Crypts prefer this or that, I have to agree with George.

Why would I want a sword that grows faster or a hedge of Crypts?
They grow plenty fast without soil, mud, substrate ferts.

That's nothing new and dates back 20 years at least.
Big root systems does not imply big root requirements.
They generally live where?

Rivers/streams............

Are those roots for uptake(they can be) or to anchor the plants
in fast flowing conditions? Seems like a simple question.

They are also amphibious plants, so they need to be able to get
nutrients from the roots obviously at some point during the
seasons.

But do they prefer root fertilization?
Many terrestrial crops have foliar ferts added to them to
increase yeilds, perhaps farmers selling Billions in crops each
year have it all wrong...... 

Preference is given in botany as "growth rate", perhpas
increases in dry weight biomass etc.

CO2 increases growth rates about 6-12 x.
So we could say that the plant "prefers" that.

Do they require this enrichment? No. Soem is available from
exhcnage with the air/bacteria etc.
Is such enrichement desirable for someone wanting slower growth?
Probably not.

But how would you design a test to show whether a plant prefers
nutrients from the roots versus the water column or both?

Tank 1: inert sand no water column ferts
Tank 2: inert sand, water column ferts(non limiting)
Tank 3: nutrient rich + sand no water column ferts
Tank 4: nutrient rich substrate + water column ferts(non
limiting)

Tank's 2 should grow slower and 3 should grow faster.
But..........that's not the case for swords or Crypts.......

Now what about tank 4?
Generally about the same as 2 for **most** plants.

There are some differences though, whether they are entirely due
to nutrient location or not is another matter.

Still, for maximum growth rates, something many aquatic plant
folks complain about keeping up with and desiring slower growth
rates, and mix of the 2 locations would provide the best
solution.

It would extend the time before substrate depletion and supply
all the water column only plant types(Riccia, Java ferns etc).

Likewise, a substrate fert will allow a back up source in case
you slack on the water column ferts or run them leaner.

Somke plants do appear to prefer some substrate ferts, HC, a
couple of Crypt species(rare ones that are typically grown
emergent) Rotala green etc. Generally pretty limited groups,
hardly a generalization that is often stated on line by folks.

"Swords and Crypts prefer root fertilization......"

If you think or believe this, you certainly will want to re
evaluate you belief and prove to yourself that this is not the
case.

I have similar swords that started out small, the next thing I
know I have a tree on my hand........I used RFUG's and swords
got way too big, there was nothing in the substrate plain old
sand, but I used water column ferts. I also used no RFUG's and
still got the same growth rates.

So you might want to reconsider such mythical advice.........
I have done more tank test than about anyone here on this issue
goign back now well over a decade, I have not seen these claims
hold true.

Anyone that's used non nutrient substrates, CO2 etc and has
grown monster swords will also attest to this observation.
And George does not even use high light............

Now will swords grow witrh substrate feets and no CO2?
Yes, but will they grow faster/better with water column ferts
and CO2, most definitely.

If someone has issues with their swords in a higher tech CO2
enriched tank, it's because you are not providing good
CO2/nutrients to these weeds, you might assume you are, but you
have over looked something. You have confounding factors
influencing your conclusions.

That does not in anyway imply that swords prefer substrate
ferts, nor low tech methods.

I have issues with Swords and most Crypts becoming too weedy and
growing too much and getting too large. So I reduce the light
down for slower growth rates. If I desire even slower growth
rates, I remove CO2.

But I have good CO2 and nutrients, other might not and draw a
different conclusion blame excess nutrients on poor
growth.......but if that where really the case, why do I have
such huge fast growing weeds?

Such a hypothesis cannot possibly be correct based on
observations(I think between George, myself and Neil, we have
20000 years of experience:-)
and simple things like CO2 enrichment increasing plant growth
and especially when it comes to limited aquatic submersed
systems.

Please entertain me how CO2 limited systems will grow faster
than a CO2 enriched one everything else being equal(non
limiting).

Regards, 
Tom Barr

www.BarrReport.com


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