I'd generally agree that something of the magnitude of 1 dkh is caused by something other than coral growth (GFO, dosing, PH change, etc.). But, these things happen and often have a delayed impact on alk. When I start up nitrate dosing for example once it reaches my lower limit , the effect's of the nitrate dosing are delayed. So how do I know when the additional alk consumption spurred by NO3 dosing kicks in without daily testing? I have enough things fluctuating at this point in my tank that daily testing is still required. But yes the swings are getting much smaller as my tank matures and I haven't had anything more than .5 dkh in quite a while. My daily change is typically in the .1-.2 range.