Swapping to BBB but what about CalHypo

[waterbear]

As a rule of thumb, for every 10 ppm of FC added by trichlor you are also adding 6 ppm of CYA and with dichlor every 10 ppm FC added adds 9 ppm CYA so if you only need to make small adjustments in CYA they can be useful but if you are trying to bump up the CYA by 20 ppm or so you are probably better off just adding the CYA directly.
As far as calcium goes, for every 10 ppm FC added by Cal Hypo you are adding about 7 ppm calcium so it's not going to be the best way to try and raise the calcium when it is low.