Mp40w Es setup

[boots]

So I received my my first mp40 last night. Man was I excited!however I have a few questions. My tank thicness is between the 3/8&1/2 inch so I set it to the 1/2 inch setting on the pin spacer should I have gone to the 3/8? I also used the rubber gasket should I use this or remove it. Lastly I have set it to reef crest mode at about 75% on a 180 gall bow front which mode does everyone find to be the best reef crest or lagoonal.

Thanks for your input
Boots