Here's the link, it calculates a bunch of other things too.


General Hydroponics - Indoor Hydroponic Gardening, Hobby Gardening, Hydroponics System and Hydroponics Experiments

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Herb the gift, from the Earth, and what's from the earth is of the greatest worth. So before u knock it, try it first, you'll see it's a blessing and it's not a curse. - Ben Harper