# Thread: How much fluoride is present in tap water?

1. ## How much fluoride is present in tap water?

Hey, can anyone show me how to work this out please

What quantity of fluoride (0.7 ppm) is present in two liters of tap water?

Thankyooou ^^

2. Originally Posted by Dan167
Hey, can anyone show me how to work this out please

What quantity of fluoride (0.7 ppm) is present in two liters of tap water?

Thankyooou ^^
1 ppm means 1 part per million parts.

Now note: 1,000 mg = 1 g and there's 1,000 g in 1 L. Therefore there's 1,000,000 mg in 1 L. So 1ppm means 1 mg in 1 L of water.

Therefore 0.7 ppm means 0.7 mg in 1 L of water.

Therefore 1.4 mg of flouride in 2 L of water.

3. Originally Posted by mr fantastic
1 ppm means 1 part per million parts.

Now note: 1,000 mg = 1 g and there's 1,000 g in 1 L. Therefore there's 1,000,000 mg in 1 L. So 1ppm means 1 mg in 1 L of water.

Therefore 0.7 ppm means 0.7 mg in 1 L of water.

Therefore 1.4 mg of flouride in 2 L of water.
Wow thats easy, thanks a lot