Algae or Dirt

[kerrypope]

Hope this finds all well as we begin the summer! Opened my pool Memorial Day which was about 4 weeks behind where I usually am, but to the point;
1) opened normally everything looking good, fair numbers for start-up but being behind my schedule a little algea.
2) took about a week to look great and stayed that way for 2 weeks, now still LOOKS good with good numbers (posted) but when normal brushing a dark tinge cloud arises, no visible patches, ?algea?
3) I do live rural (eg. Gravel roads, farm fields) so maybe just dust or dirt? It has been rather windy!
4) Full sun 9.5hours
FC 5.0
CC .5 one drop 10 ml sample
PH 7.5
TA 100
CYA 30

 

[Bama Rambler]

I don't see anything but the CC that makes me think algae, but if you want to be sure you can run an OCLT and that'll settle it.

 

[kerrypope]

Did and no significant loss.

 

[kerrypope]

If I do another one this evening should I raise my chlorine any before beginning the test?

 

[Bama Rambler]

If you already passed it then I wouldn't worry about it. If you just want to do it for peace of mind, just leave your FC at the normal level. No use raising it above normal just for the test.

 

[woodyp]

More than likely just VERY fine dirt. Just like you, I shocked, passed everything etc. Filter just won't pick up super fine stuff. Finally broke down and vac'd to waste a third of the pool at a time. DE in the sand filter wouldn't even catch it. Much better now!