The problem is how do you KNOW they're preggo? You see movement right? What if they are harassed to the point they reabsorb the pups before that movement is seen halfway through the pregnanacy?
I understand the isolation thing, and have no problem doing it. When I reworked my 750 I glued braces to the bottom of the tank and drilled holes in the top of the tank to brace the divider. Works great. My last 2 CB pups were born behind it.
No UV. Hard to justify the $700-$1K it would cost to put one on a 1200 gallon system when people can't even agree on them being necessary. There's plenty of people here breeding and keeping rays just fine without any UVs.
As far as meds, again hard to justify spending several hundred dollars to shotgun medicate a 1200 gallon system. IF I knew they needed it no problem, but I don't. Throwing that much money in the water hoping for better rays sounds like a really expensive wishing well.
Not trying to be a prick, just sharing the view from my side of the fence......
Believe me this (Marble breeding project) is quickly turning into one of the most difficult things I've ever set out to attempt. I spent less time winning a DB Drag world championship then I've spent trying to establish a top shelf breeding group. The frustration is so great it's bordering on hatred. I love them so much that not being able to breed them is making me hate them. Which has spurred a change of heart towards a lot of things.