quarantine tank ???

[Myka]

So do I change the water (100% water change) between removing of the fish and adding of new fish to the quarantine tank? or do I just add new fish to the exsiting water that the old fish just left?

I would just do a typical 10% water change just to freshen it up, no need to do a 100% water change unless the last fish died in the QT. Provided the last fish left the QT in good health there is no reason to believe the water in the QT is infected.

I'm using a magunim hot filter for the filtration on my quarantine tank, so once the tank is empty should I throw out the filter media? Or between adding of fish? If nothing was wrong can I just add the filter assy (with media) to my sump to keep it going? Or clean the whole filter assy and put a new filter media in and then put it on the sump?

Provided the last fish was in good health when it left the QT, you can put the filter assembly in the sump as is if you want. A bit risky imo though because you rarely know "for sure" that the new fish is disease free.

As well with all the equipment that I'm using in the quarantine tank, right now it only sees the quartine tank, but once I take it down can I use the equipment that was in the quarantine tank in my display tank?

Sure, why not?