Glass Top Question

[Honeyman]

I got a glass top for my 65gal but unsure about the the Oxygen exchange with only the back 2" being open.

My tank has a HOB Refugium (which is open) as well as a HOB Skimmer. Are these 2 sufficient enough to oxygenate the tank?

I need some sort of a top, as I am tired of cleaning my lights from the salt splatter and considering taking off the hinged part and leaving the middle section.

 

[Bad Company]

What about spacers under the glass top? Home Depot sell some nice silicone spacers with adhesive on one side...