Spraying down DE Filter Cartridge's while still fixed in the filter?

[TFP_Addict]

If I were to spray down the cartridges a quick once over is there any downside to that?

I know that after you clean the cartridge's thoroughly, you have add diatomaceous earth to your skimmer.
What exactly does this do? It binds to the cartridge and protects them? I've never really understand the science behind this.

So for example, if I had a layer of dirt to the top each cartridge, but the Filter was pretty much clean as a whole. Could I just rinse that dirt off to the bottom and be fine? OR would I have to add more DE?

 

[Cwiggs]

If you rinse off any DE from the grids you need to replace the DE. If you only rinsed off a little bit I'm not sure how you would be able to tell how much DE you need to put back in.

Typically people either backwash the filter, which makes you loose less DE; Or they clean the grids completely which gets rid of all the DE.

DE isn't super expensive so I wouldn't spray them down for a quick once over, I'd just back wash, or clean them all the way.

What exactly does this do? It binds to the cartridge and protects them? I've never really understand the science behind this.

The DE sticks to the grids and all the water has to then go through the DE to get out of the filter. The DE can filter very small particles, which is what actually filters the particles from your pool. I'm sure there is more info on DE filters in the wiki if you want to learn more.