Just follow chem_geek's advice . . . don't add anything, just bubble some air through the water and the TA will fall and the Ph will rise.

I would imagine the water fall will work fine to bubble air into the water. If you have the ability though, make an injection quill out of some pvc (actually about anything would work - even an old garden hose with some tiny holes drilled in it and one end plugged and the other end hose clamped to an air line fitting) and hook up a large air compressor if you have one (those tiny ones you see to run nail guns, etc. wont work - they'll run and run and put very little air in the pool, they just don't have the capacity needed).

Last year we had a 12' Intex above ground and I rigged a fountain up and it worked but was slow. Later one of the kids tried to climb up on the ring of the pool and let a ton of water out. After I refilled it the darn TA was high again. This time I hooked up an air compressor and it fell very quickly.

Just calm down and follow the advice given and everything will work out.

/Steve