Deja if you're pretty sure lack of 02 is the answer then good. If you can get the root stuff I would....my hydro guy swears its the best bar none.

Never heard about the penny theory so can't recommend it myself and would worry about possible copper toxicity.

Cannazym is the best to prevent root rot....all conditions given being the same and Root Exeluater (however the heck it's spelled) is best to TREAT root rot.

Stay on top with the H202.....it'll be the only thing killing the pathogens.

What number ppm were you/are you at?