I also have a floating Santa Monica - but a smaller footprint one because I bought it to fit my old sump space which was very limited. I added that to an existing tank so everything was going already. Went straight into the cade day one (but also so did almost all the water)Also, if I do pursue the insane 4 return route, I could route the chords through the original return slots in the overflow...
Also, @danieyella what type of ATS do you have? @sp1187 i know you have the floating Santa Monica model. When did you start running it after the initial cycle
Edit. Question is for both of you lovely hoomans