White sediment on pool bottom

[lee872]

I had a new liner installed 3 weeks ago and am still bringing chemicals to level after filling with town water. White sediment appeared this week. There is nothing collecting in my vac filter, and when I brush, it puffs up to a powder with a slightly tannish color, reappears when it settles. It appeared about 5 days ago, during a cold week when I didn't do anything but rinse skimmer and add bleach. Yesterday I backwashed, vacuumed, added salt, and shock level of bleach. I haven't had any CC, shock level was just to give me a little leeway in starting the SWG during another cold wet week when I won't want to do pool chores. The white stuff is back this morning. There is not a lot, it's an amount that would look like normal sediment that needs vacuuming except it's white. I can't figure out a way to add video, and I didn't take an image before I brushed, so description will have to do for now.

Liner guarantee requires testing to pool store levels, but I haven't added any calcium yet. Don't know whether that could help or hurt. Today I added Borax to bring PH to 7.5. I want to get some stabilizer in pool, but am reluctant in case I need to SLAM due to white stuff.

A couple of things that might be relevant. When I add DE to my filter, some DE works its way into the pool, vacuums up, doesn't reappear. The white stuff is is not DE, i mention it in case the DE discharge from filter is relevant. I did add DE 2 weeks ago, but did a large back wash yesterday so it's probably gone. And there was no white sediment the first week after I added DE.

Town water has metals, although it doesn't test at pool stores. Water has turned brown twice since new fill, but 2 quarts of PoolStyle Super Metal Control each time has kept browning at bay.

My questions are what to do about white stuff? what to do with chemicals?

Water temp is hovering at 60 +/- 2
FC 6.5
CC 0
TA 90
PH 7.4
CH 90
CYA 20 assumed, no sun today so didn't test, was less than 20 2 weeks ago, added 2 gallons liquid stabilizer
Salt 3300 using strip, turned on SWG this morning

 

[Richard320]

Pollen, maybe?

Go look around at windowsills and patio furniture and cars that don't move much and see if they're covered with it.

 

[lee872]

I wondered about pollen too. I don't think so, showers have been holding down the pollen levels for the last week or so. And it's usually yellow, I've never seen white.

 

[pooldv]

My next guess would be dead algae. Perform the Overnight FC Loss Test (OCLT) to see if something is using chlorine in your pool.

 

[lee872]

Cold, wet, and early mornings has had me avoiding OCLT, but the time has come ... I'll do it this week and post results. Should I hold off on chemicals until then?

 

[pooldv]

No shame in avoiding cold, wet, early mornings! I avoid them for any one of those reasons, I would maintain as normal until then.