Thanks M. Nguyen.
I posted 3200-3500 because I calculated 2 times with 2 different methods. My pond in so irregular shape so I measured carefully each side and turn, each dept...etc. came up with 3200 gs. Second time I Measured all straight edges and used flexible tape measured all curves then brought total measurements into CAD design and the software indicated 3500 gallons. As my most earlier posts, I made 80-85% water change prior to first dose of ProformC because I had salt it it, tested with salt method (using liquid test kit which is 2 1/2 years old solution) and came up with 4800-5000 gallons (added 80 pounds of salt and test kit read 2.2%) The past Saturday I purchased the Koimetic tester and this good digital instrument read the water I saved in a jar 3.2% so 3000 gallons it is on the safe side.
I checked with a few dealers and no one offer the scrape and scope, will make more call today.
Thanks M.
Thanh.