Re: Aquatic Plants Digest V1 #195

Hoa writes:

>You meant you were serious?  It seemed like such an inefficient way of
>injecting CO2, considering the low concentration of CO2 in your breath.
>It must be a very big bag of air you use.  How long does it take to fill it
>with your breath?  And you are not just injecting CO2, but O2 and N2
>(mostly).  How do you deal with undissolved gasses?  (I don't have the
>original posting anymore and I can't remember what you used for the reaction
>chamber.)  I'm sorry if I had offended you, but I thought you were joking.  ;-)
Yes, I am serious.  The method really works well.  From one four inch plant
I have produced,in two years, a bushel (I am not exaggerating!) of Anubias
nana which I sold for $80.00 at a tropical fish store.  They were grown
underwater in a 75 gallon tank.  It takes me 4 to 5 minutes to blow up a
bag.  I do it while stepping up and down from a chair to increase my CO2
production.  If it did it while sitting down, it might take 15 to 20
minutes.  A bag does three fifteen gallon or one 55 gallon, or even one 75
gallon tank for two days.  The rate of bubble production by the plants does
not seem to fall off until the third day.  I knew that using low percentage
CO2 works because I grew aquatic plants for my master's degree research
under algae-free (almost sterile) conditions in flasks, and I found that
bubbling the flask with 1% CO2 produced very rapid growth which was limited
by the light intensity, rather than the CO2 supply.  The method of delivery
is through an airstone.  I have an air pump enclosed in a small bag with
the electric cord and air tube coming out of one end.  I attatch the tube
from the big bag that I blew up to the other end and use the pump to empty
the big bag into my tanks.  I don't know the volume of the big bag, but I
can find out if you are interested.  The open end is bunched around a 1/2
in diameter tube and tied with rubber bands, and, therefore, the volume is
less than the value stated on the box.  I once had some dry ice, and I
threw some pieces in my 55 and let them lie on the bottom, bubbling away
until they were gone.  I was surprised how many pieces I had to throw in
before the pH got down to 6.5, which is what I get with my breath.  The O2
in the bag may be 2 or 3 percent lower than in atmospheric air, but I
havn't seen any ill effects on fish or anything else.  The N2 in the bag
should be essentially the same as that in atmospheric air, and so it should
not change the amount of dissolved N2 in the water.

It works for two reasons, I think.  One is that atmospheric air has .003%
CO2, and, if you increase it to 3%, you are increasing the concentration by
1000.  Since CO2 is fairly soluble in water, such an increase would allow a
big increase in the amount in solution.  The second reason is that a person
puts out quite a lot of CO2.  I read somewhere that a resting adult puts
out as much heat as a 100 watt light bulb.  When exercising, as I do when
stepping on and off the chair, the metabolic rate can be 10 to 15 times

 I wrote this up in the Aquatic Gardener back around 1991 or so.  I can get
you  the reference, if you are interested.

Paul Krombholz