yeah i agree with rob! wether its a terestrial plant or a hydra coral, they tend to suck the elements dirrectly out of the enviromnent they need in order to grow! sometimes it doesn't always follow a set pattern, but more often that not u will after alittle bit of time get used to the general uptake of your animals!thats untill u add a new
Ca loving addition..lol your shouldn't have to dose a huge amount as of now, its the coral wall builders that use the most
Ca as building blocks for structual formation and growth!
really make an effert to test frequently untill u get a handle on where u are sitting.
all the other parameters have come up a smidge which is good!
heres to stable conditions!
lol
have u managed to check your Mg levels?
just to add the over run for perspective> with every ingredient in your mixing bowl
alk is most like the binding agent! limits those unwanted swings in
Ph that u were concerned about. proper Mg levels helps u as the doser get as much
Ca in usable form to the corals.
Ca is an all u can eat food basket (that yogi would be dribbling over) that
Ca building corals will readily absorb to grow bigger>just for u wildman!
icon under there name and give them Reputation points
V-series Productions 
USA 
*runs back to his parabolic telescope*