Why is my acrylic really runny?

I am doing acrylic nails and have been watching many YouTube videos and noticed that my acrylic is really runny compared with what I see in videos. I have minimised the amount of acrylic liquid on my brush to ensure that it is not saturated but as soon as I get my ball of acrylic and place it on the nail it spread and runs making it extremely hard to work. This usually results in thin acrylic on the nails and I can't seem to "build up" the acrylic as it keeps flattening like a pancake. Can anyone suggest why this is happening? Could it have something to do with the brand of acrylic powder or brand of acrylic liquid?