"Sir Douglas Cook" wrote in message ...
....

I am just suggesting that just one person out there might just want
to try this "FREE" CO2 PUMP before they fork out the cash.

Since I add baking soda one 2L bottle will last over a month,
and after all my homemade CO2 filter is simple to make and
did I say "FREE", "FREE", "FREE".
The nice part about it is most of my friends that have CO2 pumps
said to me that "If only they tried my method first they wouldn't have
bought a C02 pump" because they care about their fish primarily.

I think you will find that many more than one person have used DIY CO2
methods in the past and many more are still using them today. I for
one used it for the best part of 7 years and while it's relatively
cheap, it unfortunately does not give a steady CO2 output like a
pressurized CO2 setup provides. Seeing that fluctuations seem to be
your biggest concern, you will find that a pressurized setup will give
you more stable levels in the best interest of your fish. And of
course, it's very nice to simply forget about it for a year until it
needs to be filled again. As with the rest of your arguments, I think
someone may be leading you the wrong way personally, regardless of
their education or scientific status. While I'm sure it's not
intentional, it is close minded of them. There are limits in all
things and I believe they are looking at it from one extreme only, CO2
in planted tanks with fish is just fine if kept in reasonable
concentrations (15-30ppm in general). I think if you mention this to
these people they will agree. If not, well.... I'm sorry but they are
mistaken.

If you are interested, here's an article on DIY CO2 that I posted a
little while ago, it's nothing new and there are many ways of doing
it.

http://www.gpodio.com/diy_co2.asp

And if you want to dig even further or perhaps print something out for
your friends to look over:

http://www.qsl.net/w2wdx/aquaria/diyco2.html

Now I'm not sure if you were just stating a point or if your friends
really do wish they were doing the DIY CO2 thing rather than
pressurized, if so, I will buy their CO2 equipment off them and even
throw in a couple empty soda bottles to get them started ;-)

Trust me, we are not all crazy here! :-)

Regards
Giancarlo Podio
www.gpodio.com