Thanks, I felt bad for the poor thing. Its sick and then I stick it in a violent tank. Knock on wood, everyone else looks okay so far.
I really don't want to run an extra 'just in case' tank all the time. Now that my tank is stocked, its pretty rare to be bringing in new fish, and knock on wood, that was the first time I had to remove a fish for illness. But I do want to be prepared if there is a next time.
I saw a little Toms Dive Clean Mini Internal Filter online. It looks small enough I could run it on my 10g all the time (in conjunction with the filter already in use of course), and then pop it into the 5g if I need (and will be cycled). I like the spray bar it has, and that it has a sponge media and I can remove the carbon as it doesn't sound like you can change it. The sponge filter I have now, the powerhead is just too strong. And I hate the noisy air pumps. Plus I don't want a sponge filter in my display tanks. So a little internal filter might be a good solution.
And I'll pick up a little heater. I thought I had an extra somewhere, but I can't find it.
I'll also pick up a bottle of medicine or two to keep on hand just in case.
Anything else to keep in this little emergency fish kit? I don't have a lid for the tank. Any good diy quick fixes for that?