im new to this forum. i've been reading a lot here these day, because i just bought a house with an older gunite pool around 16x36 , 40-50 years old. it's in ok shape, but there some thing i need to clarify.
first, my problem.: for the past 2 week i've been running the pump ( the water is a new fill) and i was getting 9 psi. 2 days ago i did pressure wash the pool border and that as made a lot of paint to peel and go to water. i did use the manual cleaner that plug in the skimmer and all seem fine. i did remove A LOT of paint scaling.
Now, i can't get the pressure in the system to go back. it's struggle from 2 to 5 psi, there is an amount of air in the pump basket right when i start and that dont go. the skimmer suction seem pretty good, but the return jet is barely having pressure. i did open the pump to check the impeller , there was a plastic screw jammed, but after removing the situation is unchanged. When i stop the pump i feel there might be a small air leek in the pump lid, but it's really small , it need to be adressed with new o-ring but i dont thing this i the pressure problem cause. the pump is a 1hp jacuzzi magnum. can that be the pump that getting weak?
other question. when do i know it's time for new sand?, how long is a normal backwash?