AH Supply finished enclosures and aquarium tops

[aychamo]

Hey guys;

I'm looking at getting the AH supply finished enclosure for a 48" tank and putting 4x55w kit in it.

Since this enclosure sits on top of the tank, I need to put a piece of clear plastic or acrylic or whatever on it, right? Where would one locate sucha thing? Should I have it cut for me locally?

Obviously, I should leave some uncovered, at the back of the tank so that there is room for the filters and whatever else to run in and out. Should I try to cut it to similar dimensions as the finished enclosure's? To make it easy on me, I could pour chemicals and feed the fish from the back side of the tank where I left room for the filters.

But, it seems like it would be a pain to have to pull the large enclosure off, and then a large piece of glass off each time I want to tweak the inside of the tank.

Alternatilvy, I've seen these types of lights:

http://www.aquarium-supply.biz/order...alight_pc.html

(The 4x65 watt kit, except it comes with 2 actnit bulbs?? wtf!) The sit a few inches above the aquarium, but that also would require me to have a piece of acrylic or wahtever above the tank, right?

What exactly is the purpose of the acrylic above the aquarium? Is it to protect the lights? Or is it stop the fish from jumping out? How big of a concern is this? I could see a problem if say I bumped my enclosure and it fell in the water.

What do you guys think? And what do you do personally regarding the top of your aquarium?