Scott,
You don't want to use ammonia, it's a base! I been told that Mir-acid
is the way to go for acid loving CP, but I used fertilizers of several
different formulations. Peter's 20-20-20 is what I'm using now. It's
diluted to about 1/3 strength of what is recommended for houseplants.
Mir-acid probably works the best, though I haven't tried it yet.
Also, wait for the seedling to get a couple of leaves before using
fert. as they should have enough from their cotyledon and they can
still damp-off. Fertilizer will also feed fungus and bacteria
which cause damp-off so I wait till they are past that stage.
Dave Evans