I had my above ground pool open for 10 days with no chemicals. Frankly, my family was in it so much that I just forgot since the water was clear and clean. It was not used for about 4 days and boom!! I had a greenish pool and thousands of tiny (about 2 cm long) little blackish worms swimming all through the pool. I fished out a few of the worms and in the air, they died and turned bright red. I bought chemicals to shock and balance the water (and it seems to be killing the creatures) but now my family is freaked out and doesn't want to go back in. I have video and pictures, but I'm not sure how to post those. Any idea what they could be? Thanks!