CH,
Please post your test numbers as Poconos suggested. Your problem almost certainly lies, at least mostly, with your chemistry.

That said, the TR60 is a pretty small filter for a 30,000 gallon pool. What is the size of your pump? There's some possibility you're overdriving the filter which is causing channeling in the sand. That would allow at least some of the water to flow through those channels, essentially without being filtered at all.