Re: [APD] Non CO2 methods

[Thomas Barr <tcbiii at yahoo_com>]

> 1) I don't think that Walstad is much into water testing. 
> After you know
> the chemistry of the local tap water, and determined that it
> isn't poison,
> it shouldn't be necessary.

That's a big plus and wise idea, most slack on testing as it is.
I decided to test and see what could be learned using a non CO2
approach.

I have my own modified version that is independent if one choses
to be of a substrate nutrients source.

This way I am much better able to focus on uptake and mass
losses, it's much tougher to measure nutrients in the
sediments:)

I am also better able to assess what issues some plants might
have and what nutrients are often lacking in expecting soil and
fish waste alone(both vary through time and with respect to
increased biomass of the plants...and thus these manifest
themselves as deficiencies with increasing time/biomass)

Generally the soil is low in K+ and GH, a little Fe/Mn helps.
Often times I found the NO3 declining or PO4.

Rather than running a tank that gets stalled and builds up NO3,
due to say a **lack of K+** (not becuase there are too many fish
etc), I was able to test things like K+ (yes, I have a nice K+
colorimeter).
To my knowledge, no one in the planted hobby has ever done a
critical K+ test........

Certainly as a group, few Non CO2 folks test much. 
But testing tells you a lot when you do it critically and think
about what might be ocurring.

You need not do it for years, just a few weeks to see.
Then you try a prediction out and see.

I found few species that normally folks say can only be grown in
CO2 high light tanks doing much better in a classic non CO2
method when we added a buit PO4/NO3/GH once a week at low
levels.

Not enough to have to test and worry, but just enough to relieve
the stronger limitions by various nutrients.

Growth is slow, so small amounts of ferts can have a fairly good
impact.

So the goal is not testing also, like EI, but estimating and
general range so testing is not required as much/at all.

You predict the uptake rates, you skip a week of dosing to clear
out the tank's excesses, but the ferts like adding K+ allow a
better balance and usage of NO3 and other nutrients.

You have a very wide effective range using non CO2 and the
trends occur slow, no big deal if you let something go a week,
vs a CO2 tank might have issues after a day or two.

> 2) "At least 2 Watts per gallon", "More light, more plant
> growth, less
> algae", and "replacing tubes every 9 months" is more in line
> with a high
> tech tank requiring CO2 injection and adding fertilizers. 
> Walstad's tanks
> about 50 gallons in size appear to normally have about 1 Watt
> per gallon of
> low tech fluorescent lighting.

1-2 w/gal of NO T12 or T8 lighting is about right.
I can use more likely because I add enough plant biomass to
start with.

I also cook /boil or mineralize the soil prior to use.
This removes the pesky NH4 which is fairly easy to show causes
algae as well as fish health related issues.
Zeolite might be added as well as it'll expire and turn to
biomedia after 1 month anyway.

Still, you want to reduce and remove all the NH4 you can for
either methods you might try, CO2 or non CO2.

Plants adapt to low CO2 and they also adapt well to low lighting
if you provide them with good stable levels of CO2(low or high)
and with stable lighting, preferable the type that has a good
spread over the entire top of the tank evenly.

> 3) Adding a powerhead is unnecessary and can reduce the
> available CO2.

I use a cansiter or a HOB for every one of them.
PH's do not reduce the CO2 really,surface moevemnt can bring
more CO2 when it's lower, this might also limit algae(low CO2)
much like low NH4 limits new growth.
The CO2 is present early on during the day, the plants remove
it, then the tank is choked without CO2 and what litlte is
brought in, is removed via the plants and their well adapted low
CO2 scavaging systems.

Fairly hostile place for new germinated algae.

 I have measured the CO2 very carefully in the tanks at low
levels, I want to do some more testing before I talk about it
more.

 
> I guess my regime is a modified Walstad scheme.  I gave up on
> soil
> substrates after about 3 years of experimenting.  I couldn't
> get a soil
> locally that was either not contaminated or wasn't so hot in
> nutrients.

You should boil it 10 minutes to oxidize the NH4 or soak in
shallow tray for 2-3 weeks to mineralize the NH4 to NO3 mainly.
Then use it.

  The
> water was always yellow and I guess I was always ending up
> using too much
> soil in the mix.  I finally went to 100% Schultz Aquatic Plant
> soil and
> waited for the substrate to get really dirty, and am using a
> couple of
> hundred Endler's to fertilize the tanks.  The type of gravel
> shouldn?t be
> too important, as how dirty it is.  The tank essentially makes
> its own soil
> over time.

"Dirty sand methods" of the Dutch, that goes back about 50 years
or more. But there's no need to wait months for this.
See the above suggestion.

  My previous amount of light is estimated to be
> about ? Watt per
> gallon as compared to the two new AHS 96 Watt CFs that I just
> put on the 125
> gallon tank.  That's 1.54 Watts per gallon with the new
> lights, and its many
> times brighter than the old setup.  The algae did not go away
> and the plants
> would not grow well until about a year ago when I purchased a
> glass top for
> the 125 gallon tank, and then the tank appeared to magically
> transform
> itself.  I figure with the glass top I was now conserving CO2
> much better.

How about reduced the lighting intensity by 20% or so?
That's what drives the system before CO2, the CO2 uptake is
light driven, not the other way around(Idea).
 
> Also, whether it is a high light-high tech tank or a low tech
> tank, the
> plants in either case are purifying the water.
> 
> Steve Pituch


Yep, that they are, but the method defines the growth rate and
management approaches.

Less light= Less CO2, less growth= less uptake= less demand.
There are lower limits and upper limits, plants need a min
amount to live and grow and they have a max growth rate as well
using CO2 on the upper end.

But they grow for many of the same reasons, and adapt to various
conditions fairly well, if they are stable and not condusive to
algae inducement.

Regards, 
Tom Barr

www.BarrReport.com



 
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