I'm on one of the islands here doing some diving...the reefs are beautiful!...would collecting the water in a bottle for my two nanos actually do anything in your opinion? Tbh, i doubt a handful of sand would be missed either. I mean i head back to the city in the morning but the hotel I'm at is literally right on the water with beautiful corals right off the shore. Would the water actually make a difference in coral health in your opinion? (Like a liter for a 10 gallon nano)