Ick/Velvet - Unsure of what to do

[crystain]

My fiance's 58 gal FOWLR (with plans to convert to reef) tank contracted some unhappiness from a ***** purchased fish...it was a hard lesson to learn. Other particulars...4 - 5 inch DSB, 60 lbs LR. Tank has been running for about 6 months.
At the time that the diseased fish was introduced into the tank, she had 7 small chromis, a watchman goby, and a firefish...all of which had been very healthy and happy for months. In the past month she has lost two chromis, the goby, and the firefish.
The diseased fish she purchased began to show symptom almost immediately upon introduction into the tank, and included "gasping", wedging bewteen rocks, lying on its side at the bottom of the tank, and at the end noticeable dots all over its body. I am uncertain as to whether what I described is ick or velvet. As soon as the fish died, she hyposalinated the tank...and also added some copper treatment, which I understand is not the best thing if she intends to have any corals in the future. But she continues to lose fish.
The question is how to eradicate the pathogen from the tank. It has been suggested that she remove the fish to a Q tank and treat them with copper and to remove all the water from the show tank, soak the LR in fresh (non saline) water, add a cycle inducer...and basically cycle the tank all over. This seems very radical to me and was wondering if anyone has any other options. I have read that the sand can be removed and soaked in fresh water for a few weeks to kill the off the "bugs" while leaving them with no home in the tank.

 

[beth]

Yes, it was a very bad idea to treat the main tank with anything, let alone copper. Your friend will need to set up a separate hospital tank to treat ALL fish. Since you are not even sure which disease you are dealing with, then I’d recommend to treat using copper, which is an effective treatment for both ick and velvet.
If you can, get Cupamine. Gradually bring the hospital tank that has the sick fish in it up to a copper concentration .30-.35ppm. Your friend will need an accurate test kit to ensure adequate dosing. The hospital tank should not have any rock or substrate in it as the copper will be absorbed by these materials making maintaining therapeutic levels of the medication in the tank very difficult.
The treatment tank, if it is not established, will need to be constantly attended in order to maintain the copper level needed, while, at the same time, maintaining good water quality [via water changes]. This can be done by dosing replacement water with copper at the appropriate level prior to doing a water change in the hospital tank.
The copper levels in tank must be maintained for 3 wks after all visible signs of the disease have gone. Following the 3 weeks, copper dosing can be dropped, allowing the fish to remain in the hospital for another week to ensure wellness before re-introduction to the main tank.

 

[crystain]

Thanks for the info Beth.
But what can be done about the show tank with little nasties still living in the sandbed? Will it die off eventually if there are no fishies to infect? Should the salinity be dropped while the fishies are in the Qt tank?