Which way should water inlet in above ground pool point up or down?

It is best to have the inlet facing up so that it breaks the top surface of water for better skimming action.

Also turn it slightly so that can achieve a rotation of water around the pool forcing all top debris to the skimmer and most bottom dirt to the center for easier cleaning.

Also with the water having movement on the top it reduces the amount of chlorine burnt off by the sun.

Hope that helps.

Kevin

accurate pool and spa service