re:CO2 injection via wet/dry return

>The reason for enclosed wet/dry filtration is to trap the ambient
>CO2 as it is returned from other tanks in the system and reintroduce
>it to the same tanks.  
>All plumbing parts are easily found at the local hardware.  The initial
>expense of an enclosed wet/dry is soon outweighed by the resulting
>plant growth.  It is extremely important to have the equipment on timers
>so that the CO2 injection corresponds with the lighting.
>I'd like to hear from others who have tried something similar and learn of
>their successes and problems encountered.

I am currently running CO2 into the drip chamber of a former trickle filter on 
my 55g tank (will be torn down for moving this week).  I've found it a good way 
to get CO2 into suspension without using an auxillary pump for a CO2 reactor 
(my reactor pump kept clogging up with yeast slime).  I run my CO2 day-in and 
day-out and don't see much in the way of pH swings.  I am having a little 
problem with my siphon stability when my water gets supersaturated with O2 (O2 
bubbles form inside the negative pressure portion of the siphon) and am working 
on a solution to that problem.

After I'm done moving, I'll no longer have trickle filters of any sort, but 
rather just settling tanks where I can capture any fry/shrimp/snails that go 
down my tank drains (photos have been scanned and are forthcoming if Erik wants 
to add them to the Krib, and after I get the captions done).  I'll probably 
introduce CO2 at the siphon overflow point (outside the tank, "waterfall" in my 
designs).  I keep my settling tanks well covered to reduce evaporation and will 
probably have a pretty good CO2 recapture rate inside the settling tank.  I'll 
post updates on effectiveness/problems after I get the CO2 set up and running.

David W. Webb
Enterprise Computing Provisioning
Texas Instruments Inc. Dallas, TX USA
(214) 575-3443 (voice)  MSGID:       DAWB
(214) 575-4853 (fax)    Internet:    dwebb at ti_com
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