I just bought a 4 stage ro unit and it is a counter top model. It hooks up to the faucet. My question is ,can it lay flat or would it work better upright Thanks
The position doesn't matter other than if it has DI that portion will work best if it is vertical and fills from the bottom and exits the top. If its just RO it does not matter. The only thing I suggest is the first time you use it you may want to start it running them pick it up and slowly rotate it all around in different positions to release any trapped air in the filters and housings. When you disconnect it once done make sure you leave the housings full of water so the membrane and DI if it has it do not dry out.