 So what's urine brine? Imagine if you have a cup of urine and you leave it out in the sun for a very long time and all the water is gone. Urine brine is all the things in your urine that, you know, make it stink, basically. Got it. Returning to our membranes. So we have this forward osmosis system, right, where just by osmotic pressure, the water travels via this membrane into the salt solution.