Hi, I am new to CaRX. I got a geo612 with arm coarse media. My 160 gal sps heavy reef consumes 1.5 dKH per day. Over four days I have titrated the CaRX pH down to pH 5.9 and 50 ml/min delivered by versa pump, I can keep up with alk consumption over 24 hours but I see a 1 DkH diurnal swing which I had flattened out much more when using 2 part previously (see attached trident data; CaRX came online 12/23). I set the bpm at 90 using milwaukee regulator and the CO2 solenoid mostly stays on. I am only seeing 20dKH in the effluent at the 50 ml/min. I hesitate to use the reborn reformulated media due to pictures online of the cigarette butts, glass, and astropod shell contamination. I ordered a 2 gallon secondary chamber SMC618 from GEO but it will take a month to get here. I am wondering your guys experience with a 1 dKh diurnal swing and whether this is a problem for the corals. Anecdotally, I think I am seeing less polyp extension but I am a biased observer. I am able to completely stabilize tank pH at 8.2-8.4 dirunal swing with Kalk reactor no problem (see attached pH data, kalk reactor was brought online 12/24). So excess CO2 in the effluent is adequately converted to bicarbonate by the Kalk.