Put some coral chip at the outlet from the denitrator for the water to drip slowly to resolve the ph issues . As u will need about a month or more to let the denitrator to kick in. Once it kick in u will see the sulphur colour will change to darker tone like orangy yellow . Control the teeoff from the inlet feed if u can get a valve to control the drip freely at the outlet . Or u can join the outlet to a CR if u have one and it will do very well melting the CR media with low ph water from the denitrator to get good calcium ppm happy reefing