You need to make sure the circulation is sufficient in your tank to gas off the CO2 in the reactor output. Do you drip the output in a high flow area of your tank, such as near the skimmer or sump?
effleunt ph was at 6.4 then went up to6.8 im at about 30 bubbles per minute or as close as i can get with my regulator. its an old blueline. the lowest i can get the PSI on it is 19. which a little high but should be ok