Thanks to ALL responded.
I'm able to get red of my problem by reducing light to the minimum and stop
feeding fish for 2 days. its almost all clear "for now"
"Greg G." wrote in message
...

For what it is worth, I just recovered from a severe outbreak of
'green water' and the solution was simple.

As to what caused it, a recent water change comes to mind. When the
tank was first set up, the tap water here was perfect, pH of about 7,
KH around 2. For some reason, the water quality has changed
radically, and the pH is now 8.4 (!) and the hardness remains the
same. Apparently the water company has decided to add 'something' to
the water. I have also had trouble with terrestrial flower seedlings
damping off when using the tap water. Blamed everything - pots, peat
moss, bad seeds. Bleached everything and started over, and got the
same results. Turned out to be something in the water - I started
using rain water, and it stopped! I really think there is bacteria
and fungus in the crappy (big) city tap water here!

Anyway, the solution - for me - was a thorough cleaning of the debris
on the bottom of the tank, couple with a 20% water change, and a
temporary reduction in lighting to 1/2 normal duration. Within days,
the green water cleared up, and now the tank never looked better.

All of this has me thinking seriously about an RO unit. I know my
Orchids would appreciate it as well. When I kept reef tanks in
Florida, it made the difference between success and failure.

Greg