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Re: Science Project, chemical names, brittle plants

>From: sierrahotel <sierrahotel at flex_net>

>My son is considering a science fair project using a DIY CO2 to compare
>plant growth in parallel tanks with and without CO2.  Any suggestions as
>to what sort of plant, substrate, fertilization etc. should be used
>would be appreciated.   We are thinking elegans (elodea)
>
>We have 7.2 Ph, hard well water.  Plan to buy couple of cheap 5 gals and
>hang shop light across them, measure plant growth in millimeters/day.
>
>BTW..we use 3 Liter instead of 2 liter bottles using the same 3/4 cup of
>sugar recommended for the 2 liter size with water to fill bottle within
>3" of top.  Comparing notes with other people using 2 Liter recipe, I
>believe I am getting a lot faster gas generation rate.
>
I am not sure what plant you are using.  elegans is not a species of the
genus Elodea or the related genus, Eigeria.  In any event, I would not
recomend any plants in these genera because they can extract CO2 from the
bicarbonate ion and can raise the pH to near 11 in strong light.  I would
recommend Hygrophila polysperma as a plant which does not have the ability
to utilize bicarbonate directly, but can only utilize free CO2 in the
water.  This plant will respond much more to CO2 additions.

Measuring plant growth in millimeters per day sounds difficult to do
accurately.  If you can get your hands on a balance, measuring weight gains
is easier to do, and more acccurate.


>From: "Brian " <brihead at ipa_net>
>Subject: Chemical Names
>
>......While looking through the fertilizer section in my friendly
>neighborhood >Lowe's today I saw two chemicals that I hope can be used in
>PMDD, unfortunately
>I'm no chemist, nope not even a class in college, and I don't recognize the
>names exactly.  The first was known as "Nitrate of Soda" the second was
>"Muriate of Potash K20" both carried the brand name of Hoffmans.  From what
>I've read I'm guessing that the muriate of potash is the form of potassium
>that I'm looking for although the package said something like "Maximum Cl
>60%".  I've got the epsom salt covered.   I would be very appreciative for
>info from anyone who can tell me whether these two chemicals are the ones
>that I want.
>Thanks  -Brian

Nitrate of Soda is sodium nitrate, NaNO3, which is not often used by
aquatic gardeners because potassium nitrate is also available, and this
supplies both potassium and nitrogen.  Muriate of Potash is really
potassium chloride.  The package description of the contents in terms of
K2O is quite misleading. It is just KCl.
>


>From: Kenny Song <kensong at pc_jaring.my>
>Subject: Brittle Plants
>

>...I have a question which I hope someone can answer. After I overcame my
>Green >Water, my plants suddenly grew very fast. My Java Ferns sprouted
>many new >leaves and my Vallisneara sent out runners everywhere!
>
>My question is why are the Vals very brittle? They are medium green and
>some >new shoots have curled leaves. Are they short of certain nutrients?
>I did not >dose since the Green Water outbreak (fear of another attack)
>and have cut back >my light level and CO2 dosing slightly.
>
>Can plants be propagating so quickly and yet be starved of nutrients? My
>>substrate is 3.5 inches thick with a bottom 1 inch layer of Commercial
>(JBL) >substrate mix.
>
>Thanks for any (all) help.
>
The rapid growth is probably a result of an increase of nutrients,
resulting from the decomposition of the green water algae and increased
light (even though you did cut your light back), now that the green water
is gone.  The main reason is the increased nutrient availability.  Green
water algae are heavy consumers of nitrogen and phosphorus.

The curled leaves on the new shoots of Vallisneria could be either calcium
deficiency or boron deficiency. Usually white stripes accompany the leaf
curling in these deficiencies.  If you are sure there is calcium present in
the water, try just a trace of boric acid---less than a milligram of boron
per liter.  If neither the calcium nor the boron works, then the symptoms
may be due to some kind of toxicity.  You don't happen to have any nylon
cloth in the water do you?  Nylon slowly releases a substance that cause
symptoms resembling calcium deficiency in aquatic plants.

Paul Krombholz, in chilly Central Mississippi, where we dropped from 62 F.
at midnight to 30 F by 8:00 AM.