GPM for backwashing Quad DE 80?

[tsunami]

Is there a minimum/maximum GPM requirement for backwashing a Quad DE 80? It has a 2" slide valve on it and I was thinking of backwashing it for 3 minutes at maybe 30 GPM or so. Any recommendations?

I've looked in the filter manual and couldn't find any mention of it. But I've heard that there's a possibility of blowing out the cartridges when plumbing the Quad DE backwards(output/input are opposite on a Quad DE vs. a regular DE filter). But wouldn't backwashing the filter have the same effect on the cartridges as plumbing it backwards?

 

[JasonLion]

That filter is rated for something like 150 GPM, you are not going to damage it by backwashing. A conventional cartridge filter can be damaged by backwashing, or plumbing backwards, but not the kind you have.

I would use a higher GPM, perhaps something around 60 GPM. You want to be sure to wash out as much of the DE as possible.