I wanted to ask that same question, but I thought they were extra framed viewing ports for cheaper smaller 3/4" glass panels. Now you know why I didn't ask LOL.
I wanted to ask that same question, but I thought they were extra framed viewing ports for cheaper smaller 3/4" glass panels. Now you know why I didn't ask LOL.
With a 50x99 piece of 2" acrylic there's no need for any other viewing windows. No one is going to be back there amongst the filtration to see in from there anyway.