Our reactors are probably the same. It is the big green one w/ suction cups.
Co2 enters the reactor where the water exits.  The documentation said that 3 to
5 times the tank volume should circulate through the reactor in an hour.  My
tank is a 110 show (kh-3, gh-6 w/ tetra kits).  With the smaller powerhead I
wasn't seeing any changes in the ph.  When I switched to the larger one, I was
able to get the ph to stay around 7.3 for one week. It was tough to adjust
though. Since the co2 enters the reactor where the water exits, it was very easy
to just blow it out of the reactor.

>>It seems strange to me that it works fine for a day. One would think that the 
reactor either works or it does not. Are there possibly other factors at work
How reliable is your controller? How about your needle valve? How about the
pressure in 
your CO2 tank? What type of substrate do you have? And if your ph was bouncing
from 8.0 
to 9.0, wasn't this wreaking havoc with your fish as well as making your plant
wildly erratic?<<

  I agree that it seems strange and I'm not sure if it is just the reactor.  My
controller, needle valve and solenoid are all Sandpoint and they seem to work
fine. Controller turns the co2 on when the ph hits 7.3 and the co2 comes out at
a steady 1 bubble per second.
  Substrate is Estes Aquarium Gravel "Bit o' Walnut"  ( I love the names these
people come up with <g>)
   And yes, shamefully, the ph has been playing havic with my tank. I've lost 6
ottos, one by one.  First hair algae took over, then I was plagued with
blue/green.  The blue green is now gone, and the hair algae dissapeared the week
I had the ph under control--but the hair algae is back.  1 bubble/second seems
like a lot of co2 to me, but do you think I just need to turn it up?  I'm afraid
of gasing the fish.

  I now have one clown pleco and 4 rummy noses in the tank.  I really need to
figure this out because I'm expecting a baby in a few weeks (hence why the tank
hasn't been receiving priority time).  The tank has to be self-sufficient by the
time I go into the hospital. I'm afraid I'm going to come home to dead fish and
general tank chaos!!

Thanks a lot!!

Sharon Stewart
102402,2256 at Compuserve_com