Am going to retest water parameters later today. About the awesome goldfish, there's some great advice. WHEN they get over 6" ! And while they are all 1" or under, what size tank? I looked up the intex pool also; $50 for that is very cost effective.
As far as Alabama rivers having koi: it's possible, but highly unlikely. I've run around in the lakes here for over 50 years & have never seen any or heard of anyone else that did.
Global warming that's causing Alabama temps to increase says if there are koi, they'll soon be all dead. Now summers here see a heat index in the triple digits for months. Even some of the natural born fishes are affected by the heat. That's my environmental soapbox for the day!
I would have to search my soul for the answer of what's right. There are also other dangers such as wild & feral cats/dogs, coyotes/wolves, as well as stupid humans. For now, the Fishy Five will remain inside & well cared for.
Thanx everyone! (Off soapbox---for now . . .)
Quote: "Live each day as if it's your last. And treat our families of nature as though it's their last. . . Because it just might be."