16600 IG vinyl pool
FC 5.0
CC 0
PH 7.6
CYA 38
TA high at 200 but because it's vinyl we aren't worried about that
Sand filter

We also keep getting something in the pool. Even though the water was crystal clear we kept getting little blobs of something in the bottom, never anything on the sides, just the bottom. We were worried it was mustard algae so took the steps out of the pool, shocked the heck out of it, vacuumed to waste.

What we discovered after more than a week of experimenting was, whatever it is, it is coming out of the filter. If we don't run the filter the pool stays crystal clear with no little blobs. AFter reading this above posts and the description of pollen, I think that's probably what we have. We've always had to vacuum these blobs very slowly or they cloud up and disappear into the water.

Since our filter and sand are only four summers old, we really don't want to have to change the sand, and from reading, it sounds like it wouldn't matter anyway, because pollen will just keep going through the filter. I am intrigued by Carl's mention of adding DE to the filter thru the skimmer. I read the post that he's used only 5# of DE over the last 2 seasons and was wondering, for our size of pool, how much to start with?

I should also add, we live at the end of a cul-de-sac that acts like a wind tunnel blowing everything our way, and are in the heart of the San Joaquin valley in CA, so there's more than enough pollen blowing around to explain our funky phenomenom

Thank you in advance.

Mary