Neon tetras disease...how do I treat them?

[Naughts]

It's not just you Barry. My neons had this. Other people on here have had neons with the same illness. I tried salt and I tried Esha 2000, normal dose and maximum dose, nothing worked. I let them live out their lives unless they were suffering (unable to eat). I have one left, he never had any symptoms so must be immune to this virus.

 

[Barry Tetra]

I’m setting up new 20 gal qt tank.

Are substrate necessary for the tank?
What kind of filter are the best?

 

[Fish4dawin]

I’m setting up new 20 gal qt tank.

Are substrate necessary for the tank?
What kind of filter are the best?

Substrate depends on the fish you plan to quaratine. I would always suggest sand as all fish love it and if you plan to quarantine corys, they won't damage their barbels.

 

[Naughts]

I’m setting up new 20 gal qt tank.

Are substrate necessary for the tank?
What kind of filter are the best?

Substrate is not necessary but the thinnest covering of play sand will help them feel secure by blocking the reflection/ glare. You can then throw it away each time without wasting or costing too much.
A sponge filter is hard to beat. You can place the sponge part inside another tank's filter to build the beneficial bacteria ready for the quarantine tank. Some people recently said don't bother with established filters for quarantine tanks, but for me it works because I quarantine for 4 weeks at least and I have a busy life so cannot be tied to daily water changes if it's not necessary.

 

[Kyle E.]

I am not sure I have every had my tank at a point where all of the fish are healthy for more than a few weeks... You are not alone.