I have DE in the sand filter. I had replaced the sand this season, last year had a sand leak in the filter that I fixed in the off season. I did notice that the first time I backwashed some sand came out, just guessing but probably around 5 lbs. Not sure if that would make a difference.

It's not algae here are my numbers.

FC 12
CC 0
TA 100
PH 7.4
CYA 100

It really could be linked to the mowing. We've had a ton of rain here in Mass. this past couple of months and we need to cut the grass every 3 days. I'm going to vacuum today with the skimmer sock and panty hose on the return and see what I can get out.

I'm just worried about vacuuming to waste...won't that empty out alot of my pool? It's only 7500 gallons so it's a matter of minutes before I lose an inch.

We have 2 big dogs...if there are any cats in the area...we don't see them :-)