Measurement in cups of kind soil vs Nature's living soil?

[Greenpassion]

Hello again. Tons of questions as usual. This one is in regards 2 using kind soil which I have in my current first grow, in 3 gallon cloth pots, growing autos. I was instructed to use 21 cups of kind soil which would be 3 lb, in the bottom of each 3 gallon grow bag. Which I did and things are great. In my search to try to find a better price on kind soil. I came across a very similar product called Natures living soil. It seems to be a bit more concentrated and it also needs to be cooked for a week or so after it is mixed with the base regular soilless mix that I will use, Pro mix bx. The people at Nature's living soil told me that 4 cups is 1 lb. So that would mean 12 cups would be 3 lb and that would mean that I used quite a bit too much kind soil with these ones that I have currently growing. I used 21 cups in each grow bag . So which is it? I am confused. How many cups of soil makes a pound? Anybody out there using kind soil or Nature's living soil have any info? I am planning on using the natures living soil in my photoperiod Plants, in 5 gallon grow bags. The seeds aren't here yet, but I'd like to be prepared and feel like I know what I'm doing haha!

[BurningTeddy]

I think what the soil weighs would only depend on what exatly is in it right? 7 cups of a lighter soil and 4 cups of a heavier soil could weigh the same as each other.

Do you have a kitchen scale? Should be fairly easy to weigh it yourself.

[Greenpassion]

Yes. After posting that I got to thinking about it and I realize it has to do with the weight. I guess that the natures living soil is more concentrated and heavier than kind soil. Therefore it would take less cups. I have a bad habit I've jumping two questions before muling things over for a while...

[D.A.A.S.69]

Greenpassion, 7cups of KindSoil is equal to 1pound, in a 3gallon smartpot, you will need 21cups of KindSoil.
It's written on the KindSoils, bag.
PS- all soil weighs different amounts. That's kinda like does a cup of rocks, weigh the same as a cup of feathers. Lol. Jus kidn.

[Greenpassion]

Lol! After I wrote that I realized that had to do with the weight of the soil and the concentration Etc. Rocks and feathers! Duh lol!