if i were you i would blame the poor coverage on trying to do it on cement board. since pond armors service is so good you could probably call em up and say, "hey, one of your guys told me using cement board is a good thing to do but he never told me i'll get way worse coverage, now i'm out of pond armor and money to finish sealing my tank. what can you guys do to help me?"
Yeah it ended up being 3/4" starfire. Had I gone with the regular float glass it would have only been $950.00.
113" in length is what jacked the price up.. Had I gone with a smaller 8' window it would have been even cheaper.. But no, I had to be stubborn and wanted to have a giant window... lol