We're in the middle of our Texas pool build and getting ready to plaster. We opted for Tropics blue mini pebble but our PB modified the shell content. He reduced the amount of shell from the standard mix and will set it in instead of mixing (to increase visibility). We want to increase the abalone shell content but I have no idea how many bags we should add. The pool is approximately 16k gallons and we are being offered a price of $200 per bag. Thanks for any assistance.