do another one, just don't move it around too much. keep the end of the hose in one place, and below the water level when you fill it back up.
your amminia may skyrocket again if your tank is overstocked. what else is in the tank besides the angels?
Just keep up on the tank maintenance and water changes. You are using a good liquid test kit, vice dip strips?
Most meds will recommend removing carbon when you use them, but not necessarily the filter pads. I run sponge filters in addition to standard filtration on all tanks. If I ever have to med a tank that endangers the bacteria, I do a large water change and vac to begin with. DO my treatment, then pull sponges from other tanks to get my bacteria back faster.