For what it's worth, this year when I was opening my pool, my water had a green tint for several days, even though all my numbers were good and I had no algae presence whatsoever. I read somewhere here on TFP that prolonged high chlorine levels would do that. A few days after I got it down from the shock level to a consistent 5, it cleared up and has been sparkling ever since. Not saying that this is your problem, but it's something to consider.