re: High light without CO2

>From: Stephen.Pushak at hcsd_hac.com
>Date: Thu, 24 Aug 95 2:25:35 PDT
>Subject: Re: Milky water & High light w/o CO2
>Shaji wrote:
>> Karen, are you saying that you *need* CO2 and and trace elements to
>> keep a tank in balance if you have high light?  To, me, it seems you
>> are implying that without CO2 and trace elements, you cannot cultivate
>> high-light plants.  My experience is that it is possible to use high
>> light in a low-tech tank, but you do need to keep the fish load down
>> and ensure that the nutrient levels in the tank don't get high enough
>> to cause an algae problem.
>Yes but on the other hand, if you have enough plants to avoid algae and
>there is high light and a lack of CO2, many types of plants would resort
>to biogenic decalcification to rob CO2 for photosynthesis from carbonates.

This assumes that there a significant amount of carbonates exist, and
that the plants are growing fast enough to resort to decalcification.
In my water, carbonate hardness is next to 0 (< 1 DKH), and I don't
see a problem.  Even in harder water, you may not have a problem if
you don't have too many fast growing plants, or if growth is limited
by other factors.

>I think you'd have to choose the plants carefully;
>which ones have you had success with? I'd say for the average aquarist
>wishing to try a variety of plants, (s)he'd have more success with CO2.

No doubt.  And even CO2 is not a cure-all.  I suspect that almost
everyone with CO2 injection has a few plants that just don't do well.

If you go with the low-tech approach, you have to experiment more.
And I don't think that you should automatically eliminate high-light
plants from a low-tech setup.  I have grown Cabomba, Pennywort, R.
macarantha, dwarf chain swords and hairgrass without CO2 in bright
natural lighting.

>From: krandall at world_std.com (Karen A Randall)
>Date: Thu, 24 Aug 1995 09:01:29 -0400
>Subject: Milky Water, Kribs and Light
>> Karen, are you saying that you *need* CO2 and and trace elements to
>> keep a tank in balance if you have high light?  
>What I'm saying is that you *need* to balance the light in the tank with 
>adequate amounts of CO2 and trace elements.  If you can do this without 
>artificial supplementation, that's terrific... but it's a difficult 
>balancing act that most people can't achieve.

I'll take that as a yes :-).

There are people on this list who say that low-tech tanks, period, are
an exercise in futility. Most newcomers to the aquatic gardening area
will probably agree, at least for a year or so.  You seem to be saying
that low-tech tanks are possible, but that you are best off sticking
with low light and slow-growing plants.

I think that are just too many variables in raising plants the
low-tech way, and that experimenting to figure out what works for you
is the only way.  You have to figure out how to complement the
nutrients in your local water.  You have to figure out what mix of
plants works for you.  And IMO, lighting is one of the parameters
that you have to play with.  I don't axiomatically rule out high light
in a low-tech tank.

For instance, I have a 10 gallon tank with one big 4" fish and 40
watts of lighting.  A clump of Java moss is the only vegetation.  The
tank is pretty much algae-free, although by all accounts, it should be
an algae soup.  It has stayed that way for several years.

I also have a couple of outdoor tubs that are in direct sunlight for
part of the day, but have next to no algae.  In fact, these tanks
produce some of my best plants, even better than the ones grown in my
CO2-injected setup.

In short, I'd say if someone wants high light in a low-tech setup,
it's worth a try.

 Shaji Bhaskar,                                             bhaskar at bnr_ca
 BNR, 35 Davis Dr., RTP, NC 27709, USA                      (919) 991 7125