denitrator

i just built my self a coil denitrator, and since it uses the same size tubing as my calcium reactor i have the calcium reactor output conected to the input of the coil denitrator.(also reduces need for an extra pump)
does any one see any problems with this? or should i reverse the order(denitrator ouput to reactor input)? the ouput of these two then goes into my skimmer.
my rational is that the denitrator uses oxygen free water, so why not use the output of the reactor, possible problem is that it is co2 rich.
ive also read that some people have the reactor second because the effluent from the denitratior has low ph so people run it through the reactor for buffer, but these are based on sulphur based denitrators.
appreciate any suggestions thanks.