How does dialysis rely on osmosis/diffusion

it's diluted or concentrated

in a diluted solution, you can add a lot more solute but in concentrated only a little more can be added

above statement is not a true statement about the open ocean because the open ocean has low levels of nutrients. most of the photosynthetic activity on earth occurs in the open ocean within the photic zone. organisms in the deep ocean are exposed to frigid temperatures and total darkness but it does not begin at the low-tide mark.