mysterious fish losses

[Aquamarina]

I haven't heard back from Instant Ocean yet. Hopefully I will!

We are down to 7 fish now, and the butterly fish has been returned to the main tank and its raw areas seem to be healing. The pH is still high (my tester only goes to 8.8) and we have done 9 water changes since Sat. The fish look a lot better!

Once the water is back to normal, we would like to replace some of the fish that we have lost--probably from J & L. How many fish would you quarantine at a time in a 20 gal tank? (The fish we want: 1 lunar wrasse, 2 oc. clowns, 2 blue damsels, 1 zebra damsel +?)

What are the quarantine methods that the group uses?