CFrame:lerp How to use it properly

It worked! Thanks!
Only problem is that it moves really blocky like.
I added a video so you know what I mean

It almost looks as if I was setting the CFrame to the same value but 4 studs above the original one very second. I think that is pretty much what is happening, but I wanted to use lerp so it went up smoothly. This is caused by the wait(1) but if I remove it, it just teleports to the top.
I used to use BodyVelocity, but the water just kept going up and I couldn’t really control the time it took to reach the top, so I switched to lerp.
Is there a better way to do this?