I was curious on how much acrylic this would take to build.. i was thinking it would be a lot, based on so many baffles.
If the sump were to be 60x24 ..... and a max height of 18".... and those baffles were 12" tall each... then you would need 53sq/ft of material....
Now im not sure what your cost on 10mm acrylic would be, but i do know that 12mm is $10/sq/ft there(cheaper then here,yet with the same company)
So 10mm has to be cheaper... im guessing closer to $8-9 sq/ft...
So that would give you a rough estimate on what it would cost to build out of acrylic. ($424-477)
Then again, based on having so many baffles, which would serve as supports, combined on the height of the sump, you could do 6mm acrylic... which would cut the cost almost in half.
If you can find glass cheaper, you could do 6mm glass. If you don't slope the sides, then it would make for a much easier build out of glass.
Also notable, the sides dont have to be sloped at all. I think the sloping is more for aesthetics then anything. Having that slope would make it difficult to put a lid on the sump... also, it takes away from overall sump volume...