[APD] RE: CO2 Saturation

["Douglas Guynn" <d_guynn at sbcglobal.net>]

> David Terrell" <Dave at TerrellClan_com> wrote:
> 
	>>I had posted the original question to the APD, wondering if the
reactor
> would be too short for the flow.<<
> 
If a reactor is allowing bubbles to pass through, the most sensible solution
for us is to provide more "residence time" in the reactor. This is generally
accomplished in one of two ways.

The first is to increase the length of the reactor. This is how Hagens CO2
Natural Plant System
(http://www.drsfostersmith.com/Product/Prod_Display.cfm?pcatid=8981&R=6309&N
=2004+2021+113565&in_merch=1) operates. Residence time in the reactor is
increased by lengthening the distance the CO2 bubble must travel before
exiting. You can do this in your setup by replacing the reactor you have
with 20 or 30 feet of 1/2 inch or larger hose or tubing. Not a very
practical solution for most.

The second is to decrease the water velocity through the reactor. With lower
velocities, the bubbles can overcome the downward pressure of the water
flow, and remain in the reactor until dissolved [Please note the difference
between velocity, measured in distance per unit of time (typically feet per
second) and flow, measured in volume per unit of time (typically gallons per
minute).] One way to decrease velocity is, as you have done, to decrease the
flow rate. This works well, unless you wish to maintain the flow rate as
high as possible. Another way to decrease velocity is to increase the
diameter of the reactor. In this solution, the flow rate remains high, while
the velocity of the water in the reactor is decreased due to increased cross
section. This is the method I use. It results in a highly efficient and
fairly compact reactor.

My reactor is made of clear PVC, is about 12-inches in length, and 2-inches
in diameter. It is placed in the inlet tubing of my Fluval 303. There are no
bioballs, or anything else inside the reactor. The CO2 is injected at the
top of the reactor, and stays there until dissolved in the water. It could
probably be as short as 3 or 4 inches. I have no problem with free CO2 in
the filter.

Just something to think about after you move.


Douglas Guynn
	432.368.5411
	d_guynn at sbcglobal.net

A government big enough to give you everything you want is big enough to
take everything you have. - Barry Goldwater

_______________________________________________
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com
http://www.actwin.com/mailman/listinfo.cgi/aquatic-plants