I have a 40G tank with a bunch of plants and a large cology of Endlers that goes cloudy at night then clears up every day so that by about afternoon it's crystal clear again. Has anybody ever seen anything like that? -- Richard J. Sexton richard at aquaria_net Maitland House, Bannockburn, Ontario, Canada, K0K 1Y0 +1 (613) 473 1719