Doing some reading... never had Killi Fish before...

[Magnum Man]

well, I do have a couple American Flag fish... I did not know they were Killi's reading about the 2 types of egg layers ( top & bottom ) pretty interesting... I could see setting up a 30 gallon or two down the road with them... always thought they were colorful... anything not commonly printed a newbie to killi's should know???

 

[GaryE]

First, in practical terms, killies don't exist.

How I kept (and failed with) flagfish is radically different from keeping other killies. The pupfish group is one thing, and within them, the coastal US ones are a different kettle of fish.
So advice one - every Genus is different, and within Genuses, different species can vary a lot. Do your research species by species and forget the broader categories.
I saw floridae in wide deep ditches around Orlando airport. They were in clumps of weeds, out in the main channel, surrounded by bluefin killies, least livebearers and Gambusia affinis.

 

[Colin_T]

We had American flag fish in outdoor ponds that were 1 meter square x 1 foot deep (high). They had plants and algae in and the fish were in them all year. They can tolerate temperatures down to 5C and up to 40C here. We didn't do anything special for them, we had 6 in each pond and just cleaned them out every 6 months and restocked them.