Do I have an Algae Bloom Starting? Whats normal chlorine loss?

[Junta]

How do I know if I have an algae bloom starting? I had to go out of town unexpectedly on Friday and when I returned, my chlorine was zero. There was no issues prior to this and my pool chemistry was normal. While I was gone, a lot of cr*p (literally and figuratively as we are knee deep in gypsy moth caterpillars), accumulated on our solar cover. I vacuumed, changed my DE and then shocked the pool with what I thought was enough chlorine to get it to 20-21 ppm. I didn't test it last night. But when I tested it this morning, I got these results:

FC: 16
CC: 0
pH: 7.3
TA: 120
CYA: 60

I tested this afternoon when I got back from work around 3:30 and my free chlorine was down to 15 (everything else was the same).

Am I seeing the early stages of an algae problem? Is 1 ppm loss in chlorine normal over a 9.5 hour period on a pool with the solar cover on?

Thanks!

 

[jblizzle]

Easiest way to see if stuff is starting to grow is follow the Overnight Chlorine Loss Test.

 

[Richard320]

It's certainly possible. Or you might have nipped it early.

The best way to know for sure is to run Overnight Chlorine Loss Test

 

[Junta]

Of course! Thanks folks!

 

[mm3846]

I'm losing a decent amount of FC (like 3ppm overnight and from morning till when I get home from work) but I 100% think its the caterpillar droppings eating up the chlorine. I'm also covered in it.

 

[Junta]

I'm losing a decent amount of FC (like 3ppm overnight and from morning till when I get home from work) but I 100% think its the caterpillar droppings eating up the chlorine. I'm also covered in it.

Similar pattern here. We should be able to tell soon as the caterpillars are dying off. All the trees around my yard are covered in dead caterpillars.

 

[mm3846]

Similar pattern here. We should be able to tell soon as the caterpillars are dying off. All the trees around my yard are covered in dead caterpillars.

Same. Yesterday and today noticeably less doodoo. Finally.