Oh, I forgot something, rather important at that.
Plants that are sensitive to Excel are sensitive to H2O2, and vica versa. So your vals are at risk from both
, unless they're already well acclimated to Excel, maybe even to overdoses. Anacharis is considered the most Excel sensitive plant, and I have mine acclimated to the point where it doesn't even flinch at the full, original "One-Two" with 4tbsp. H2O2 per 10G; and neither does any other plant in my tank. So it is possible that you may have no negative effects on the plants, but not guaranteed.