Thanks so much for the kind responses!
No pH amendments added- I had a feeling that the 'tincture of time' (and a bit of heat, & aeration from an airstone) would be helpful, and it was.
Long story short-the pH is now at 7.4 (one entire unit down!?!?) from last night.
Am actually happy about that as it had been normally ~ pH=8.
Am befuddled about the ammonia- I really did a vigorous agitation & removal of debris from the gravel (though I did not wash anything under tap) and several (2+ at 50%) water changes, yet my ammonia increased per this AM's reading.
Ammonia last night was 0.25ppm; is now 0.5ppm (what the ?@?!!).
Temp is 78-80F.
Could the bacteria still resident on (relatively new) aquarium fixtures/decor/filter media still be that productive for ammonia? (No fixtures were washed in tap- only in old tank water) (or SHOULD I be washing some of this stuff to decrease the ammonia production load?)
I'm guessing that yet another water change is in our future?
(it's ok, I'm game! - anything for Fred!- but I really did an aggressive change last night and am impressed with the productivity! lol (it can't just be Fred! lol)
I did clean the log by:
1) removing it from the tank
2) physically wiping it down with a clean disposable paper towel (wiped off gross debris)
3) soaking it in a warm solution of clean dechlorinated water & aquarium salt (1 T /gallon) for ~15 minutes
4) rinsing with tap water
5) soaked the log again ~10-15 minutes (to leach out any absorbed/adsorbed salt) in clean dechlorinated water.
I choose this method because I read that the salt could be effective against ich (so figured it couldn't hurt here and may be preemptive).
I also knew that the salinity of the water could be effective against bacteria/fungus (lyse bacterial/fungal cell walls by movement of cell water out of the cells in order to achieve balance (cell water moves to the salty water to try to dilute it), thereby killing the dehydrated cells.
I also figured that the salt water would not likely damage the synthetic material of the log (just an opinion).
We'll see if anything grows back!