Opening - Last year, a nightmare. This year, perfect...??

Weird, I know. We installed our inground pool in 2004. We do all of our own weekly maintenance, but we have a pool service open and close the pool for us.

2005 was a disaster. We had installed a sewer line (about 30 feet from the deep end of the pool), and installed a concrete sidewalk (about 10 feet from the shallow end of the pool). I'm guessing that all the dirt and the dust from digging caused a bunch of fine dirt/silt to get into the pool through the mesh cover. Anyway, the pool was the nastiest brownish green when we opened it last April. Took about 5-6 days, many gallons of bleach, and several bottles of 60% poly algaecide to clear it up.

This year, we opened the pool on the same date - April 30th. It was nearly crystal clear. Not a hint of green, and the deep end is clearly visible. What the heck is the difference?

This year, we used a different pool guy to close (last fall) and open this spring. He's big on using 25lb bags of sodium bicarb. He dumps one bag in during the fall, and one bag in the spring. It seems like he used one quart of poly algaecide in the fall and one quart in the spring - so there is no difference there. He also took a big empty chlorine bucket, made a bunch of holes in it, put some chlorine tabs in it (not sure how many) and tied it to one of the hook anchors. I'm guessing that probably made a difference as well, since the other company didn't do that.

I had read last year that many folks with mesh covers open in the spring to rather nasty, greenish pools - so I thought we might have the same problems every year. I was really relieved and happy to see how clear the water was this year.