Re: MK-Ultra Hempy, C02, 1000watts.
That's good to know. I don't know much about hydroton, just thought the coarseness would allow for more water in the bottom. I guess why mess with something that works so well.
Yep, Hydroton at the bottom would probably allow too much standing water because of all the space between the pebbles, that's why I would start with a 2" layer of Perlite at the bottom, and then alternate 2" layers of Perlite and Hydroton all the way to the top.
The Hempy hole is drilled about 2" up from the bottom, so the "res" would be mostly Perlite to prevent root rot issues.
The Hydroton layers will help retain more water, provide more oxygen, help secure and support the roots (thanks for adding that benefit doc), and may also help prevent the sketchiness with seedlings until the roots hit the res.
I see many possible benefits to messing with the original Hempy "recipe" by adding Hydroton, and since I don't trust the PH stability of vermiculite, I need something to replace it's water-retaining abilities. I think the Hydroton will do that and more.
To me, the essence of the Hempy is the bucket and hole. The medium can be lots of things.
I've seen some beasts grown in Hempy buckets with pure coco too, so I may be tryng that also.
Hygromite, or silica stone, is another medium that would probably rock in Hempys.
Lava rock would be another Hempy medium candidate.
Every grow is a chance to further refine and improve the method by seeing what works best and what doesn't.