This may be the strangest Hot Tub issue, ever posted here. It's already resolved, so I don't need any advice. I just had to share. I live on 10 wooded acres in Northern Michigan. We had our first frost about three weeks ago but the temperatures were in the 80s this week. The trees are beautiful and in full color. The warm weather, after a freeze, confused the oak tree moth larvea into hatching out. They were dropping from the trees on webs every where, because the leaves have turned and they have nothing to eat. They will die and it will mean less oak moths, next summer.
Here is where it get wierd. If the larvea, that look like 1/8 inch long maggots, can't find food, they drop to the ground and begin to climb. (usually back up a tree). For some reason, this time of year they only choose to climb up vynil surfaces. Luckily, my home is wood sided and my pole building is metal. Unfortunately our hot tub is vynil sided. Our window screens are vynil too. The little buggers were all over the screens and the tub and tub cover. Nothing like hundreds of worms that look like maggots all over your hot tub. They are so small that they got into the cracks everywhere. They were even between the cover vynil, where it is folded and stitched. Luckily, none made it to the tub water. I just spent 2 hours with a garden hose and brush, removing everyone that I could find.