DE not sticking to new grids

[OllieMeyer]

I have a FNS Plus 60 filter. I bought new grids last year. The old ones started to fall apart when I was cleaning them.
I noticed the next time I took the filter apart that only the top half of the grids had DE stuck to them.
I’m opening the pool and cleaned the grids again and inspected them. They look good as they should being new.
Still the DE won’t stick to them. It’s all piled up on the top of the manifold and at the bottom.
I bought a new manifold just in case the old one had a crack I couldn’t see.
Still the same issue.
I’ve been doing this for 8 years with no issues till I bought new grids.
I’ve looked the. Over many times to see if there’s a hole. Nothing.
Every time I back wash there’s not a stitch left on the grids except top and bottom. My old grids always had some stuck to them.
Anyways I’m at a loss. It’s taking forever to clean the pool.

 

[Lake Placid]

Every time I back wash there’s not a stitch left on the grids except top and bottom. My old grids always had some stuck to them.

That’s the point of the backwash, to remove dirty/spent DE from the grids/system and prepare them for a recharge. During a backwash, the DE will never fully be removed from the filter, which is the deposits you are seeing. Likely your old grids had soils/DE embedded in them and weren’t capable of releasing the spent DE as effectively as the new grids. Describe your backwash procedure please.

 

[Lake Placid]

Anyways I’m at a loss. It’s taking forever to clean the pool

Are you battling algae? What’s the condition of the pool? Are you currently slamming?

 

[1poolman1]

I have a FNS Plus 60 filter. I bought new grids last year. The old ones started to fall apart when I was cleaning them.
I noticed the next time I took the filter apart that only the top half of the grids had DE stuck to them.
I’m opening the pool and cleaned the grids again and inspected them. They look good as they should being new.
Still the DE won’t stick to them. It’s all piled up on the top of the manifold and at the bottom.
I bought a new manifold just in case the old one had a crack I couldn’t see.
Still the same issue.
I’ve been doing this for 8 years with no issues till I bought new grids.
I’ve looked the. Over many times to see if there’s a hole. Nothing.
Every time I back wash there’s not a stitch left on the grids except top and bottom. My old grids always had some stuck to them.
Anyways I’m at a loss. It’s taking forever to clean the pool.

Your new grids are doing what DE grids are supposed to do, letting the DE fall off when the pump stops so that the heavier debris stays at the bottom of the tank and the DE recoats each time the pump re-starts. They are considered "regenerative" filters.
If you found DE on the old grids after a backwash, you see whey you can't add a full charge of DE after a backwash as well. That should only be done when new or the filter torn down and all DE removed from the grids and tank. After a backwash, never add more than about 80% back.
The theory is that a backwash will remove all the DE and dirt and remove it from the filter, but with grids that have been use for a while the build-up of oils (all pool have oils in them eventually) cause the DE to stick and a backwash just can't get it all off and gone. The DE that is stuck to the grids is full of oils and dirt.
Soaking the grids overnight in a good filter-cleaning solution gets rid of toils that cause the problem. Once a year is good enough.
NEVER acid wash grids unless they have had the oils removed first or the grids will be ruined.

 

[OllieMeyer]

Thanks for the advice guys. I guess my old grids weren’t all that great and I got used to them looking a certain way and thinking that was the norm.
I am slamming the pool but the filter must be working well as it’s cleaning up quickly.