Bought a house with a index 16 x 48 pool.....it needed work. Drained and scrubbed! Spic and span. Filled it last night and came to the house today around 5pm to find the water slightly greenish. It was 80 degrees today. I came armed with chlorine, test kit sold to me by the local pool company. My pool has a rather large sand filter and it can be seen in one of brothers posts here. Anyway, it had no chlorine as it was well water. The ph was about 7. I dumped in most of a bag of "glb, shoxidzer"',and after 30mins., checked the chlorine level.....it was about 2.....my question is why is my pool turning brown and I can only barely see the bottom!!!!! It was light greenish before I started and the water was new just the night before!! Could I have had a alge problem in one day??