Planted Tank Guru
Join Date: Jun 2004
Location: Baton Rouge, LA
+1 to all above on nutrient requirements.
Wisteria's Latin name, "Hygrophila difformis", gives another hint on its behavior, as difformis means "two forms". It can change new leaf shape, size, and overall growth patterns dramatically in response to a change in the conditions in which it's grown. But it can take a little time to make the transition. And as it does, the older growth often suffers and looks terrible. At which point ramshorn snails may consider that unhealthy old growth fair game for a snack.
So if you're confident in your new macro/micro dosing, plus your existing Excel and lights, you may just have to wait a while to see positive results.