I've only very recently started dosing (and testing more tbh) using ESV Bionic. Up until recently I've been able to maintain params with just water changes. As my tank matures and I have no algae I've slowed down on the water changes so I don't alter my stability too much with the dosing and I no longer want to bottom out my NO3 and PO4 (as I was trying to keep this low while fighting uglies). I'm not yet sure on any set schedule for wc's yet as I monitor parameters... I was going to do kalk (really looked into this heavy) but I want a reliable method to track PH before I try it and I just haven't decided which I want yet...