Specific amounts of water for growing.

[BobBong]

thanx 4 the info but i thought plants used up co2 and gave out oxygen so feedin it co2 would be more benificial wouldnt it?

Co2 can only be used in HID lighting and generally requires an enclosed , relatively airtight area so that you can raise the Co2: o2 ratio. However, this is only needed if you have an enclosed area with high concentrations of o2 (or a lot of plants).

Co2 is only utilized properly by advanced growers who know what they're doing.