Ah, i didn;t catch the sensical thing... not that i;m familiar with that product, but the name does make it obvious that it has calcium at least are you adding something for Mg as well, or is that also in sensical?

as for the drainage and your watering scheduling, well, i think that kinda blows my thought out the window... twice a week doesn;t seem excessive.

when i started reading about the double cups like you mentioned I thought for a second that was going to be the ticket.. that water was sitting in the outside cup keeping the bottom layers of soil wet/mud like... but if you are emptying them of the run-off, then i don;t think thats it.

i;m kinda out of ideas, but there are several others that know far more than me that check this forum, hopefully one of them will come help ya