THE GREEN MAN SYSTEM NOW COMES WITH 19MM FITTINGS AND PIPE-WORK, BUT WHAT'S THE POINT?! Well, for those of us who have been growing in multipot systems for some time will know the importance of a wider bore irrigation. Newer growers may just think it's a marketing ploy. So in reality what's the big deal of using 19mm fittings and pipe-work? 19mm irrigation is what we call in the industry a 'pro-size', 13mm is the base standard for multi-pot grow systems, like that seen on the