If you found floating particles in your water dispensed from the reverse osmosis unit faucet, drain the tank.
Next, allow the tank to refill and check the water once again.
Occasionally carbon fines from the pre-filters can break loose into the water source, especially if the tank was not properly flushed upon installation. Refer to page 16 in the owner's manual to ensure this step has been properly performed.
If the tank has been flushed multiple times and particles are still showing up in the water source, the membrane needs to be replaced. Find replacement membranes here.