I'm with you Doug. Neither do I QT my new fish. Some people here are just good in talking about it by the book. IME as long as your fish are not stressed out your tank would be okay. Parasites are inevitable but if fish have good immune system they can fight it off. The reason why most new fish specially tangs gets ich is because of wrong acclimation. However, I do treat them individually in separate tank when parasites becomes uncontrollable.
I don't do anything different from yourself Doug. No QT tank here. But when it comes to those that run them, it is bare bones and normally managed by water changes to keep the toxic levels at 0 from all those that I've had contact with.
And for the record, I couldn't tell which fish losses that I've had could have been prevented by such, if at all, since it always ends up being a disappearance during the night after being introduced into the tank.
Those are both very common sentiments among the reefing world. And some people that follow that rule have no problems. But the rest of the aquarists that aren't as lucky usually pay for it in lost fish.
My question to anyone that doesn't quarantine:
Is it worth losing all your fish to avoid caring for the fish in a QT tank for 4 weeks?
If the answer is yes, then don't QT. If the answer is no, well... you get the picture.
If you have a healthy tank then Ich is not really a problem. I kept my tank this way for close to a year without any deaths related to disease. When it came time to switch over to my 90g tank I pulled all my fish out of my 20g, added them into my 90g running a cycled filter. The plan was to add some fish, let them get cozy and comfortable, and then drop it down to do a hyposalinity treatment to get rid of any remaning traces of ich in my tank and make sure the new fish didn't have ich.
The few fish I added in one at a time were a yellow tang, caudern cardinal, and a McCosker's wrasse. I spent approx 4 - 5 hours drip acclimating them and I added them about a week apart. The only aggression there was came from the clowns when I added the McCoskers in but I stuck them into the sump and added a few decorations to keep them happy. Nitrate never rose above 10ppm and there was never a sign of ammonia or nitrite. The pH was stable the entire time as I ran a sump and kept the lighting schedule on alternate timers. About a week after I added the last fish before I started dropping the salinity; I lost my first fish, then over the course of a week I lost all but a blenny and my clowns to marine velvet. I drove an hour away to the nearest LFS to get some copper and treated the tank for it.
All in all this cost me approx. $250. But compared to some here I am a relative newcomer to salt water. If you ask around, especially on other forums, there are many veterans that have had a similar experience and lost their entire tank or close to it due to not QTing.
Mr Saltwater Tank tv talks about it a little bit here.. His bill was $1,200 in lost fish.
So again, is it worth risking losing all your fish to avoid a 4 week QT?