Hey guys - I have a question about 2-part dosing. I have been struggling for about 2 months with 2-part dosing - trying to get my levels of alkalinity and calcium correct. My first question: how many mL/day do people dose? I am currently running mine at 120mL/day, which seems a bit high, doesn't it? My tank is a 125 gallon tank with a 40 gallon sump. So maybe 130 gallons of water total when taking rock/sand into account? That just seems like a lot? I am using the BRS 1.1 ml/minute dosers. I am dosing soda ash twice a day, once at midnight (60 mL) and once at 3am (60 mL). I am then dosing calcium at noon (60 mL) and 3pm (60 mL). My results so far haven't been great. My alkalinity seems to be staying in the correct range, but my calcium keeps dropping. Using the Red Sea test kits, here are my results: Wednesday 3/28 Alkalinity - 8 dKH Calcium - 420 ppm Sunday 4/1 Alkalinity: 9 dKH Calcium: 360 ppm Where should I go from here? Somebody told me at one point that you should dose the same amount of soda ash as calcium since they are supposed to balance each other out. But this doesn't appear to be the case for me? I tested magnesium on March 16th and it was showing 1400 ppm, so a lack of magnesium shouldn't be a problem? I do weekly 15-17 gallon water changes using Red Sea Pro Salt. My other numbers (in case they are relevant): SG: 1.026 pH: 8.21 Dissolved Oxygen: 8.2 ppm Temperature: 78 F Ammonia: 0 ppm Nitrite: 0 ppm Nitrate: 10 ppm Phosphate: 0.10 ppm My RODI water I use is measuring 0 ppm TDS. AM I dosing too much solutions? Should I lower the soda ash and leave calcium where it is? Any suggestions would be appreciated.