Lesson Learned - Do not be a stubborn woman, Listen to the advise on using a 45mil liner to begin with..... and day 8 of new liner.. Everybody has been healthy and happy. I'm starting to lean towards my problems being mainly from the intex pool liner leeching something into the water causing my fish to get ill.
I can not say this enough and likely will drive people crazy w/ this.. But Line it, line it, line it! If you go this route or are thinking about it.. since we replaced the liner not a single issue w/ the set-up other then its so darn dark... but I'm thinking a light natural sandy gravel will bring the colors/marking out best in the fish.