yellowish silt/sand? at the bottom of the pool

Martha_D

LifeTime Supporter
May 15, 2012
67
0
Putnam, NY
#1
There is a film of a yellowish silt part way up the walls and on the floor of my pool. I dont think the vacuum is totally catching everything because it seems too fine. I can brush it away easily. Could this be algae?

some important information: The door to one of my skimmers came off and I did not put it back on for a couple of days... my FC levels were very low last week (now back up), and I think I was not running my filter long enough. I am wondering if this could be sand from my filter? I backwashed it this morning and it was dirtier than usual.

any help is appreciated!
 

woodyp

Mod Squad
LifeTime Supporter
TFP Expert
Apr 18, 2010
10,206
0
East Texas
#2
Your backwash could be dirtier than usual due to algae. A sock or pantyhose held over your return can confirm filter sand or not. Test results would verify a need to shock, but I'm sure guessing YES!
 

Martha_D

LifeTime Supporter
May 15, 2012
67
0
Putnam, NY
#3
I just tested:
FC 3.5
CC 0
TA 110
CH 290
CYA 60

Ph is 7.8

Am I correct that I only need to add bleach? I will try the sock over the return, thank you. I have never shocked the pool before. Is shocking something that needs to be done from time to time regardless of levels? This is my first year maintaining the pool.

Thank you!
 

woodyp

Mod Squad
LifeTime Supporter
TFP Expert
Apr 18, 2010
10,206
0
East Texas
#4
Shocking is a PROCESS only performed when you have algae. "From time to time" is a pool store myth employed to counteract high levels of CYA that they love cause they sell more chemicals. Clear the pool, maintain it properly, and forget that shocking weekly nonsense. See shocking your pool in pool school and the CYA/Chlorine chart.