is a pump necessary

[tank]

Hi:

I am new to hydroponics and wanted to know if a pump that circulates the water is necessary. Is it okay to have free standing water if you have an oxygen pump. Also, is it okay to have a clear tank, or should it be so that light can't get in. Answers would be greatly appreciated. Thanks

[Ron]

Yes a pump is necessary and yes a clear tank will get slimy from the light hitting the water.