Mix the solute and the solvent in one container to make the solution. Do not add too much solute in the solvent as it can choke the membrane cartridge. Generally, you can mix the solute and the solvent in the ratio 1:10 of their volumes.
Cut the plastic tube into three sections; two sections 3 feet long and the third section 2 feet long.
Connect one 3-foot plastic tube at the inlet opening provided in the pressure pump and let the other end of the tube be free. Make sure the tube fits perfectly in the pump inlet and is not larger or smaller in diameter than the pump inlet opening.
Wrap the connection tightly with waterproof tape to prevent leakage from the joint. Tighten the screw or the connector provided at the pump opening to hold the tube firmly.
Connect the 2-foot plastic tube at the outlet end of the pressure pump in the same manner as you connected the first tube.
Connect the remaining end of the 2-foot plastic tube to one end of the reverse osmosis membrane cartridge. If the openings of the membrane cartridge are marked as "Inlet/Outlet," then connect to the inlet opening. Otherwise, you can connect to either of the two openings.
Connect the other 3-foot plastic tube to the outlet opening of the reverse osmosis membrane cartridge. Remember to wrap the joint with the waterproof tape and properly tighten all the connectors provided with the equipment.
Dip the free end of the plastic tube connected to the pump inlet in the prepared solution in the container. Put the loose end of the tube connected to the membrane cartridge outlet in the other empty container.
Plug the pressure pump into an electricity source and turn it on. Wait for a few minutes and ensure the pump is sucking the solution from the container.
If you see the filtered solvent emerging out of the free end of the plastic tube connected to the membrane cartridge outlet, it indicates the completion of your project.