Greetings everyone. I am battling some mustard algae, I believe, and am trying to keep my CL level above 23. Last night I raised it to about 26, this morning at 7:00 it was at 25. When I got home from work at 4:30 it was at 11. Is this a normal drop over the daylight hours? It did rain for a couple of minutes when I got home, but it was no more than 1/4 inch. My cya is 38.