Re: [APD] Re: CO2 tank question

["S. Hieber" <shieber at yahoo_com>]

Open up  the tank valve and adjust the regulator if it is
adjustable down to about 15-25 psi., then adjust the meedle
valve to control the flow. If the flow it too high unless
you turn the needle valve nearly allthe way in, then turn
the regulator down a little. a little back and forth
between the regulator and the needle valve might be
necessary to get a desireable flow rate. Measure your KH
(requires a cheap Aquarim Pharmeceuticals or Tetra test
kit) and your pH, then use the pH/KH/CO2 table to determine
how much CO2 is in the water.

Start out slow and work your way up with the CO2 rate so
that you don't put in too much too fast.

If you use a timer on a solenoid, your solenoid will
probably last longer and you'll save a little CO2. 

But your pH should remain pretty stable over a 24-hour
period even if you let the CO2 run continuously. The CO2
will build up a little over night and deplete a little by
end of day, with a pH swing of about 0.2 units, peak to
peak -- this is insignificant as pH swings go.

With a timer, you'll probably see about the same amount of
pH swing. With a relatively affordable pH controller like
the Milwaulkee on the solenoid instead of a timer, you'll
see about the same overall pH swing since the controller's
trigger points for off and on are about 0.2 units apart. 

When the CO2 tank is "filled", most of the CO2 in the tank
is liquid and the tank pressure (the high pressure side
pressure) remains the same -- roughly about 700-850 psi at
normal room temperatures. As CO2 escapes out the valve,
more of the liquid evaporates to gas and that is what holds
the tank pressure relatively constant. Once the liquid is
depleted and only gas remains, the tank pressure will
slowly decline as the gas escapes out the valve. That's
about the time you need to get a refill. The high side tank
pressure is partly how the regulator controls the low side
pressure. So if the CO2 tank pressure gets too low, some
regulators will suddenly dump the remaining CO2 all at
once. Some really good 2-stage regulators can handle all
the way down to 10 or less psi, which is generally lower
than the normal psi on the low side, without letting go --
so those nice $400 regulators don't dump. Others might dump
at a few hundred psi. Better to not let the high side
pressure get too low than than to try and use up that last
50 cents worth of gas in the tank :-)

Good luck, good fun,
Scott H.
--- Greg Idemoto <gidemoto at hotmail_com> wrote:

> 
> Once I get the put the regulator with the tank, do I
> release the CO2 valve 
> on the tank all the way and only use the JBJ regulator
> knob to adjust it? Or 
> do I only release the tank valve a certain amount?
> 
> Also, do you recommend I use the solenoid to time with my
> lights or just 
> leave it plugged in 24/7 so that it pumps CO2
> continously? I used to use 2 
> 2L DIY bottles on my 40 gallon long, so if I left the CO2
> on all the time it 
> would similar.
> 
> Looking forward to going pressurized...I used to have
> some good results with 
> DIY when I first started but lately it hasn't been
> happening.
> 
> -Greg
> 
>
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=====
Still some time to get the $59 registration rate -- it must increase as of October 28th to $79.

But the convention hotel rate is sold out!

A "leisure rate" of $119 per night might still be available at the hotel -- requires Friday night (the 12th) stay. Contact the hotel  
hotel directly at (703)920-3230. The generic reservation line may not offer you the "leisure rate."

Alternative hotel info should be posted soon.

The Annual AGA Convention, 2004, November 12-14.
aquatic-gardeners.org & gwapa.org
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