Filter grid failure for a relatively new Pentair DE filter


In The Industry
Nov 12, 2019
Dallas, TX
Today I had to have a service call after tearing down my system for a routine cleaning and being unable to figure out why I was blowing DE back into the pool when I recoated the grids. After some close inspection with the pool guy we finally saw that ALL but one of my grids and totally blown out at the bottom of the grid. There were no threads left and the bottom of the grid material on all but one of my grids was totally open ... not just a small rip ... but the entire bottom of the grid material was totally open and there was not stitching left at all or evidence of stitching. Pool guy said he had never seen this before.

No, I back-flush pretty regularly and no, I did not have any pressures on the gauge above 20 psi. I maintain my chemistry and its never been out of hand.

I am thinking I got a batch of bad grids all manufactured at the same time. Only the short grid was OK. All of the long ones were blown out. The system was 4 years old. It was an expensive day.

Anybody else experienced grid failure from Pentair grids purchased in the 2014 time frame??
I have had customers with relatively new Pentair filters 48sqft and have seen this happen a few times. I personally think Pentair put out bad grids. I have never seen this happen to older sets of grids or aftermarket sets of grids. I remember because the customers were trying to blame the guy cleaning the filter and I was the guy on one of the occasions it happened. I don't know when they were manufactured or when the distributor had purchased them originally but it's hard to explain to someone that has a pretty new filter system why the grids blew out and why it's not under warranty. So now I'm traumatized from pentair original filters. I'm kidding but I am weary now. I recommended the customers to call Pentair but I don't know if anyone did. If anyone gets any info in regards to this please post. This pic is from 2 days ago when my tech notified me. Craziest thing happened. It was originally 1 grid and it was replaced. When reassembled and tested again there was still blow back! It was taken apart again and 3 more grids had torn in the same place. Now that's the 1st time that has ever happened to anyone I know of. My advice is to double check the seams if you have pentair grids. You don't want to be trying to vac out a pool full of DE. It's not fun and very time consuming.