Hello, how can I help you today? If the original pvc damage you repaired was from freeze damage as well, then you'll almost always have more than one broken pipe, almost always the lowest in the tub. Chances are you've got a cracked plumbing manifold with several ports on it or one of the bottom suction drains still had water in it and cracked the fitting on the backside. You can stand it up on its side to look for it, but the most common way is bracing it up on concrete blocks high enough to crawl under it when you have water in it to locate it exactly and then turn it up on its side to repair it once you've found it. Keep in mind, this still may not be the last one you come across on this spa. Most of the freeze damage repairs I do, involve several different broken spots and you can never find one until you fix the worse one before it.

well, I can't really help you on that one, you have to be a Marquis dealer to have access to their plumbing diagrams etc. you should be able to just look in the equipment area and be able to tell if it has a plastic sheet bottom or a plywood bottom, and it still may not be a manifold at all, I'm just speaking from personal experience on different brands i've worked on, so it may not even have manifolds for the jets, but it was just a suggestion on things to look at. If it's not totally foam filled, I'd recommend just removing all four sides, fill it up and you may very well be able to see where it's leaking from without even jacking it up.