DE I run all sorts of hempy's, i'm currentlr running a 2lt plastic bottle with a noname in it, I love hempy.
Put your grow nutes in at 5.8-6.0 and bloom nutes at 6.2. Don't fuck around measuring run off as all your doing is giving yourself an extra headache that doesn't matter. Hempy is a simply but very effective method and combined with a media as forgiving as coco and you should have a bomb proof method of producing weed.
Good luck man!
"Weed doesn't fuck up your motivation, it just fucks up your motivation to do things that suck" Joe Rogan