Thanks for the quick responses,
The test kit I used was a Red Sea brand "Fresh Lab" test kit. I'm at work now and can't remember the exact ammonia/nitrite readings, but came away convinced they were negligible for now anyway.. but the pH concerned me.
I hadn't given any thought to the decorations or gravel. The gravel is just some generic stuff I picked up at the pet store chain. Medium sized, natural looking gravel, about 35 lbs of it, rinsed thoroughly before adding. No large rocks, wood, or anything biological besides the two fish and two live plants.
There are also three small ornaments, molded plastic "poly-resin" knickknacks, also cleaned before adding. You guys latched right on to the gravel/ornaments, could this be the missing pH link!? I'm going to test again in a few days, and this was the very first test, but just curious if this is an expected result of something i'm doing, if it's part of the cycle or if i should be worried for the two platys.
Also, thanks for the advice on moving the tank, I bet this low end tank wouldn't withstand much acrobatics! Need to get a big bucket for the move operation, but need to get something sturdy to put the tank on first!