for alk, you can dose food grade sodium bicarbonate (cheaply available), it has little effect on pH, however, if you dose sodium carbonate, it will increase pH.
dKH = 7 is still manageable, however if it is slightly higher would be more ideal.
CA try to maintain about 430 - 450, same thing, you can find food grade calcium carbonate cheaply
for your monti, do the white parts still show polyps? if not, its a goner, better to frag it away