weight of baking soda

[ekaifes]

Went to the pool store and they indicated i needed to add 9lbs of baking soda. I was told that 1 lb is equal to 2 cups, so i started by adding 6 cups which should be 3 lbs (per further instruction to break into 3 incremental doses). I am now thinking that the cup felt pretty heavy and am wondering if 2 cups is indeed 1 lb? I am fearful that I used too much and will overshoot which I am now reading would be an issue. TIA!

[PhantomAndy]

I've never measured it by the cup, but being familiar with the size of the 1lb boxes that I use for my pool I'd say 1 cup is = 1lb.

Don't worry about overshooing unless you get a reading above 200ppm.

[CarlD]

Went to the pool store and they indicated i needed to add 9lbs of baking soda. I was told that 1 lb is equal to 2 cups, so i started by adding 6 cups which should be 3 lbs (per further instruction to break into 3 incremental doses). I am now thinking that the cup felt pretty heavy and am wondering if 2 cups is indeed 1 lb? I am fearful that I used too much and will overshoot which I am now reading would be an issue. TIA!

9 lbs??? What is it, a 45,000 gallon pool?

[bizzelizze]

Yeah, really. I have 44,000 gal pool and at start up only use 8lbs of baking soda

[chem geek]

The density of powdered baking soda (tapped in the cup) is around 1.2 g/ml (solid sodium bicarbonate is 2.2 g/ml). This means that 1 cup is 10 ounces and 1 pound is 1.6 cups. So you are right that it felt heavier than they indicated.