If I SWAP Filters - sand to something else, how can I predict pressure change on low?

[toofast]

Ok, tough title...

I had an issue with my setup and my pump/filter supplying enough "back pressure" to allow my heat pump to run on low. The PB basically said he adjusted as low as possible, I finally put the smallest return jets on the three returns and I got enough "back pressure" to run my pump on low.

Now I am sick of screwing with the problems with my sand filter....it simply does not filter anything. Everything just blows through....they've swapped and tried everything, and still no filtering. My robot saves me and keep the pool clean.

But I still get a ton of junk floating....so I want to switch to a new filter, DE or Cartridge...but I am concerned about losing the ability to run my HP with my pump on low. Is there anyway to know or predict what various filters will do to my pressure.
Hopefully this makes sense....

 

[tim5055]

It makes sense, but I know of no way to calculate a pressure change.

But, I would ask - what is "blowing through"?

You say "I still get a ton of junk floating" deals with your skimmer. Is the weir door working properly? Do you have sufficient flow through the skimmer?

As to the sand filter , have you tried adding a little cellulose fiber DE replacement powder to the filter?

Now, you may have tried these things, but before I dropped the cash for a new filter I would try the cellulose and make sure my skimmer was operating properly and maybe put socks on the skimmer basket.

 

[toofast]

It makes sense, but I know of no way to calculate a pressure change.

But, I would ask - what is "blowing through"?

You say "I still get a ton of junk floating" deals with your skimmer. Is the weir door working properly? Do you have sufficient flow through the skimmer?

As to the sand filter , have you tried adding a little cellulose fiber DE replacement powder to the filter?

Now, you may have tried these things, but before I dropped the cash for a new filter I would try the cellulose and make sure my skimmer was operating properly and maybe put socks on the skimmer basket.

When I put DE powder into the filter, it ends up on in the pool.

Everything blows through the filter, expect stuff that gets stuck in the baskets.

I have a STRANGE filter that no one knows anything about nor can fix.