Increased filter pressure after adding acid?

[zachary.cayou]

Is there any reason that after adding muriatic acid to the pool, filter pressure may increase?

I’ve noticed this happen every once in a while. My pump runs on low 24/7 (and high for a few hours as well), and I have a spa spillover. Once the flow over the spa starts reducing to a trickle, it’s usually time to backwash. But often this seems to happen right after adding a few cups of acid.

It’s not a problem… I’m just curious what could maybe be happening to cause it.

 

[Texas Splash]

I can't think of any correlation.

 

[Sunnydaze]

How long after adding the acid does pressure go up and by how much? Does it resolve on its own or you have to backwash?

My guess is it's just a coincidence. I don't see how acid could do anything to plug the filter up.