Calcium precipitation while cooking rocks

I've got some diy rock going, but I used some 1month old base rock to do it. They are sortof cemented inbetween chucks of diy to get something tall enough for my 55. I'm trying to cook some phos out of the base rock while the cement cures. The ph is way high, >8.8 and the temp is high 80's.



So I've got this white crust over everything, it kinda looks like the photos of calcium precipitate but not as yellow. Makes sense that might happen under these conditions, right? But is it gonna clog up my rock if it gets in the pores? Like the crust on the heater is pretty strong stuff.