Iíve been having a problem ever since we got our pool. Every day when I check our pool, there are areas where a brown fine substance has collected around the wrinkles in our pool liner. The majority of it ends up near the middle of the pool since our pool is round and the pump pushes the water in a counter-clockwise direction. I usually just get in and kick it up during my swimming and vacuum it every couple of days. But it never fails that the very next day after I vacuum, the brown stuff is back. The water is very clear, so itís not something that keeps the water cloudy. Whatever it is, it always seems to settle on the bottom.
I initially suspected it was pollen and/or dirt. We are surrounded by oak trees and the pollen has been pretty bad this year. In fact, we have a chair in our screened back patio that has a nice layer of yellow on it. Our pool is also right next to a busy road so I also thought that could be throwing a lot of dirt into the air, and also when they cut grass near me since the trees have killed most of the grass, their mower kicks up a ton of dirt/grass.
In our first pool season, we had enough water a few times to vacuum to waste but it came back. Iíve been reading a lot of threads about pollen and dirt, but a lot of those ended up being algae issues and after a SLAM, it went away. I finally decided last night to do the OCLT. I decided to raise the pool to shock level before doing the test as I read that sometimes works better than doing it at normal levels. Here are my test results an hour after I added 2 jugs of 121oz 8.25% great value bleach at around 8PM:
I woke up around 6:20 this morning and tested the FC again: 17.
So now that Iíve eliminated an algae issue, Iím pretty confident in my initial hunch that this is possibly a mixture of pollen/dirt. Also, we had algae in our first season and when I kicked it up, it turned a cloudy white. This stuff just swirls around and disappears though I have so much that if I kick it up it turns the water visibly cloudy if Iím underwater looking across the pool. After a few hours of filtering though, the water is clear again and this stuff has settled on the bottom.
Iíve read different things on how to attack this problem but Iím not sure what method I should try. My main confusion comes from the fact that we have a sand filter. Iím just not sure if these are particles small enough that they pass through a sand filter. Does pollen and dirt usually past through a sand filter, or should it be catching this stuff? I was also wondering if panty hose used as a skimmer sock would help. I bought some knee-highs for adding CYA, and I stretched one across the skimmer. I didnít leave it in long though because it seemed like it was being stretched and would allow finer particles to get through. Does panty hose over the skimmer basket really block stuff that a sand filter wouldnít? I played with the idea of adding DE, but figured that would be a last resort as it requires it to be added whenever I backwash (though I donít do that often). I was going to get a robot vacuum but I figured Iíd have to run this thing every time I want to swim and couldnít be sure this stuff would even stay in the filter bag.
Any help with this issue would be greatly appreciated! Besides this issue, everything else with the pool is great and Iíve really been enjoying it since switching to TFPC.