CP wrote:
Does anyone really know:
Can Ich survive in an aquarium with no fish, no living animals?
I've have a 40 gal tank that my kids use.
Two months ago they bought some fish, loaches, tetras, etc.
Within 5 days I noticed Ich.
Tried to treat it with Quick Cure.
Didn't work and all fish soon died.
Changed out filter but did not change water.
Let tank run for about 6 weeks.
Kids then went and bought 5-6 Platy's and I noticed about 3-4 days later
that fish had Ich.
I've read a ton about Ich in the last day, I am actually overloaded on the
topic.
Raise your tank water temp to 87-90 degrees. Add salt. Do this, don't do
this.

You said that your first Ich treatment with Quick Cure didn't work and
all the fish died.
This really puzzles me, as QC is the best medicine (IMO) for Ich there
is (not to mention a ton of other "nasties" it kills that the bottle
doesn't list).
I have to ask....
Was the carbon removed from the filter system?
Was the QC bought new for this treatment, or had it been previously
opened and sat on a shelf somewhere?

Oh...always after treating with meds you should do a partial water
change.
You mentioned changing out the filter pad, but not changing any water.
Why is that?
Water changes are the best thing you can do for your tank.
Keep a regular schedule, and do an extra one after medication.
When ever your fish have or even don't have obvious symptoms, or have
J.A.R. (just aint right), do a water change!