Bought a house end of last summer that had an IG approx 30k gallon pool. From talking with neighbors the pool was put in nearly 30 years ago and had not been in use for several years. This was evidenced by the swamp that lay before my eyes. I have had the pool checked out and the plumbing and visible plaster are in good condition so I set upon draining and cleaning the pool so that it can be fully checked and repainted. I have emptied the pool and gotten about five years of leaves out, my question comes in here. I understand the need and reason for a hydrostatic relief valve and why it would be bad to leave the pool empty for an extended period of time, but how will i be able to paint the bottom of the pool if there is always standing water in it. I have located the valve and pulled it up and turned it 90 degrees to stand on the nubs the hold it up. I have also turned it the other 90 degrees so that it sits flush with the plug. (not sure which is open and which is closed.) Both times water has seeped back up through the main drain. Do I have a bad relief valve or will some water always come back through. I am in northwest Ohio and we have not had any substantial rain for more than a month.