I know this thread is a lttle old but I thought I'd comment.
I have a 450g tank with 380 lbs. of LR
. I can not take the risk of introducing any parasites into my main. I can't treat the main, nor can I catch a fish (unless it is near death and can't get away from me).
My point is that I can't imagine not QTing newcomers with a prophylactic treatment such as Hyposalinity.
There are pluses to having a large tank (ie very stable water) but there are also negatives (when things go wrong it is multiplied).
450g Acrylic FOWLR
380 lbs. of Live Rock
1 Yellow Tang, 1 Mono, 1 Blue Angel, 1 Foxface Lo, 1 Lunare Wrasse, 1 Snowflake Eel
1x Dolphin AS2100
1x Dolphin AM4700
72" Aqualight Pro: 4x96 Actinic, 3x150 HQI Halides, 4x1 moonlights
AquaC EV-1000 Protein Skimmer run by Dolphin AS2100
AquaUV 114 watt UV Sterilizer
2x Jager 250w
...Work in progess.....