I've recently spent a lot of time on this topic due to similar circumstances. I was trying to follow the "Paul B" approach, but I lost everything to a disease outbreak last year - it really bummed me out. Now I'm squarely in the "Copper QT every time" camp. Here are my suggestions:
- "QT" means Copper Safe or Copper Power at 2.50 ppm for 30 days, followed by two doses of Prazipro. Do not use ammonia lockers with copper; apparently it creates toxic byproducts. Instead you must monitor ammonia carefully and manage the excess through water changes.
- Read through Jay Hemdal's Quarantine Protocol on R2R: https://www.reef2reef.com/threads/current-quarantine-protocol.825055/ It might look intense, but it's really not. It boils down to a few straightforward steps and a modest equipment investment. Jay lays it out pretty clearly. The biggest commitment is your diligence.
- Get yourself a Hanna Copper checker. $50 is a pittance in this hobby, and you'll save money and sanity in the long run.
- You might get away with a 45-day fallow period in your DT. Read through the article on that topic here: https://www.reef2reef.com/threads/45-day-fallow-periods.805213/ It involves running your tank at 81°F, which is not for everyone.
- There's also some good advice on https://humble.fish
Good luck!