We recently moved and are having a new pool put in. The plumbing was completed last Tuesday and held 20 psi for 4 days. Gunite was shot Friday and pressure was still 20 psi at the end of the day. We went out of town and returned today and the pressure dropped 4 psi. I think this is normal, the temperature last week was 100 all week, but it rained everyday we were gon and te.ps were low 90's. Any input would be helpful.