I backwashed today at approximately 20 lbs as usual. I was not yet in a no-flow situation (as indicated on the heater), but the flow was surely reduced coming from the return lines. The grids have been chemically cleaned only a few days prior to going in the DE tank. Start up pressure at that time was 15. The cycle lasted only a few days until the pressure got up to 20, so I figured I might as well do it again today. These short cycles have been plaguing me ever since opening the pool end of May. And, start-up pressure has been increasingly higher as the weeks go on. What was always a start-up of 11 lbs for probably the last 20 years is now suddenly 14, 15, and climbing.
So getting back to today- immediately after backwashing, taking out the grids and using high pressure nozzle to clean them off real well, putting them back in, turning on the pump - my pressure was 19 - only ONE pound lower than before I took anything apart! This is a totally unprecedented startup pressure in my 31 years of operating the pool. And, even more amazing to me, is that I had not yet put in any DE. All this, to me, makes absolutely no sense but seems indicative of either a suction side blockage of some sort (or other blockage somewhere in the system -perhaps coming out of the pump). Or possibly issues with the pump? The gauge is brand new - one of these glycerin filled that shows 1/2 lb. increments - so it should be accurate.
The next time I take the tank apart - which will surely be soon - I want to try running the pool without the grids just to see what the start-up pressure is. .I've run the pool many times this way over the years whenever we've gone on vacation during the swimming season. That way I never have had to worry about pressure increase. The pressure without the grids has always been, without fail, an unwavering 10 or 11 lbs. IF it's that way again, then I'm really not sure what's going on with the grids or plumbing or whatever else. However, if the pressure without the grids IS unusually higher than 10-11, I think that pretty well supports my theory that more than just chemistry is at work here.
Thoughts or suggestions??
So getting back to today- immediately after backwashing, taking out the grids and using high pressure nozzle to clean them off real well, putting them back in, turning on the pump - my pressure was 19 - only ONE pound lower than before I took anything apart! This is a totally unprecedented startup pressure in my 31 years of operating the pool. And, even more amazing to me, is that I had not yet put in any DE. All this, to me, makes absolutely no sense but seems indicative of either a suction side blockage of some sort (or other blockage somewhere in the system -perhaps coming out of the pump). Or possibly issues with the pump? The gauge is brand new - one of these glycerin filled that shows 1/2 lb. increments - so it should be accurate.
The next time I take the tank apart - which will surely be soon - I want to try running the pool without the grids just to see what the start-up pressure is. .I've run the pool many times this way over the years whenever we've gone on vacation during the swimming season. That way I never have had to worry about pressure increase. The pressure without the grids has always been, without fail, an unwavering 10 or 11 lbs. IF it's that way again, then I'm really not sure what's going on with the grids or plumbing or whatever else. However, if the pressure without the grids IS unusually higher than 10-11, I think that pretty well supports my theory that more than just chemistry is at work here.
Thoughts or suggestions??