Question on a Treatment Tank

After my last experience with having the main tank affected with ich
and loosing most my fish, I learned the hard way the importance of
having a treatment tank. So I purchase a 10gal tank setup so I could
first introduce the fish in it for a couple of weeks before they go in
the main tank. I just have a few question on treatment tanks.

1.use copper when putting fish in it?

2.How often should the water be changed?

3. What type of filter? the one I have was recomended by the LFS-
intank air riser with prefilter pad.

4.How many days is it recomended to keep the fish in the tratment tank
for survalance? I had a blenny in it for 5 day and it has been eating
but iy died. I can only think I was over feeding but there was no
ammonia was 0.2
reading.

What is happening is my fish dont make it even in the treatment tank.
ammonia not high and I have been changing the water once a week. Temp
good no nitrate