That's a lot of plugs! I've never pinched out busy lizzy plugs but someone else on here might know different. I do know you have to keep them well watered or they'll just wilt. They're like sponges, they just soak it up.

I wouldn't bother to pinch out 750 plugs - life's too short! They always seem to bush out on their own without any encouragement. Agree with Thorneyside, they don't like to get very dry for long. Keep them gently moist but not soggy - but they are pretty tolerant. The main problem is mildew and there's nothing we can do about that once it gets a hold.