Nah. The Durso standpipe is for the bottom drilled tank and overflow box. It's basically so the waterfall (water going to the sump) over that box isn't as deep so it doesn't make that much noise.
I'd imagine you're using the bulk head fitting from the back and an elbow pointed downward, both hard. Likely the black. From there you could do the flex spa hose. Just need the stronger glue for pvc
to flex than the stuff used for all pvc
. Ask the plumber tech at the store which. I think it's blue.