My thought is to spray bleach on the ladder and then hose it off a half hour later or so, but I am not sure. I'll ask Ben about this. He is pretty busy this weekend and it may be a bit before he gets an answer back to us.

Regarding Polyquat, it should tell on the label what the dosage is per volume. Be aware that it will cause your FC to drop drastically, so you'll need to add more chlorine after a few hours to bring it back up. Having said that, I have a question for you. Did Ben suggest that you add Polyquat when you were battling your water problems before you drained and refilled? If that is the case, you don't have to add Polyquat to a fresh fill but you can if you want. It actually isn't necessary to use algaecides if water chemistry is maintained properly. I never do. But, it is ok to do so if you want.