Thank you "goodreef" for your many helpful comments and suggestions. I ran out yesterday and bought a medication for internal bacterial infections (metronidazole). I know this entire problem will take time to correct, but I'm in it for the long haul.

I will continue my water changes as it does seem to "perk" up the fish (no more than 25% at a time for 3 days in a row). My water values are still the same as when I started so I'm not sure if thats good or bad (good for less stress on the fish or bad because the water is not stabilizing down to a lower pH properly). I have begun using RO water from my local fish store. No more tap water for any reason. I don't want to cause any more stress...

The fish do have a very densly planted tank with a few floating branches (all plastic plants of various kind) and a few hiding places under the large driftwood decoration (fake). There are no signs of fighting. The tetras swim together and are eager to eat. The platys swin next to the tetra without any fin nipping. I think I'm good there...

No more fish will be added until I am POSITIVE that all is well with the tank water and the fish health.

Again, thank you for your concern and suggestions - Crikee