Pumice for Hempy Buckets

J.R. Toker

Active Member
I have tons of pumice I can use. Is it okay to use only pumice as my medium? I like the idea that I can use it over and over forever (as it never breaks down) and that it's PH neutral. My main goal is to never have to buy grow medium again and it'll be nice to use what I already have.

I've also thought about adding about a 1/3 of vermiculite for some water retention and silica, but I'm not sure if that's a good idea or not.

Any help is appreciated :-)
 
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Roger A. Shrubber

Well-Known Member
my concern is that pumice is very abrasive, which may not be good for your roots. otherwise, just about anything that will offer support to your plants and decent air penetration of the plants roots should work as a medium, as long as it is an inert substance
 

hotrodharley

Well-Known Member
my concern is that pumice is very abrasive, which may not be good for your roots. otherwise, just about anything that will offer support to your plants and decent air penetration of the plants roots should work as a medium, as long as it is an inert substance
It also degrades fairly quickly because it’s so soft. I gave up after finding sludge in the bottom of the reservoir for weeks. Even after rinsing the hell out of it.
 

Dizzl136

Member
I went ahead and used pumice and vermiculite 50/50 for my hempy buckets on my first grow ever.

Seeds sprouted on the 19th of April in straight Coco, transplanted to hempy buckets on 3rd May

Feeding hydrocrop hydrosol as per manufacturer recommended feed schedule
Occasionally use kelp based fertilizer in addition to the hydrosol.
Foliar feeding with the same kelp spray every 2 weeks.

Plants are under the intense equatorial sun for 12 hours each day and go under 300w LED for another six hours daily.

1x girl scout cookies
1x Frisian dew
1x Mimosa evo
1x kosher Kush
2x BCN critical XXL Auto

The pumice works really well.
It is definitely more robust than perlite and is somewhat heavier too. Keeps the buckets really stable.
I am using large pumice chunks in the reservoir and 3to5 mm along with similarly sized vermiculite to fill them up.IMG_20220519_195420.jpgIMG_20220519_195517.jpgIMG_20220519_195510.jpgIMG_20220519_195503.jpg
 

Roger A. Shrubber

Well-Known Member
I went ahead and used pumice and vermiculite 50/50 for my hempy buckets on my first grow ever.

Seeds sprouted on the 19th of April in straight Coco, transplanted to hempy buckets on 3rd May

Feeding hydrocrop hydrosol as per manufacturer recommended feed schedule
Occasionally use kelp based fertilizer in addition to the hydrosol.
Foliar feeding with the same kelp spray every 2 weeks.

Plants are under the intense equatorial sun for 12 hours each day and go under 300w LED for another six hours daily.

1x girl scout cookies
1x Frisian dew
1x Mimosa evo
1x kosher Kush
2x BCN critical XXL Auto

The pumice works really well.
It is definitely more robust than perlite and is somewhat heavier too. Keeps the buckets really stable.
I am using large pumice chunks in the reservoir and 3to5 mm along with similarly sized vermiculite to fill them up.View attachment 5137040View attachment 5137041View attachment 5137042View attachment 5137043
nice results. you'll really have to keep on top of watering though. one of the good things about coco is if you have to go away for a couple of days, a good watering will see them through, because of the coco's water absorption. i do not see pumice being so forgiving.
 

Dizzl136

Member
nice results. you'll really have to keep on top of watering though. one of the good things about coco is if you have to go away for a couple of days, a good watering will see them through, because of the coco's water absorption. i do not see pumice being so forgiving.
Thanks for the advice. My mix has 50% vermiculite which greatly helps water loss.

At the moment they get about 1.5 litres every 3 days. The reservoir is usually 99% dry by this point, but the media is still slightly moist. Watered to roughly 20% runoff.

The method so far has been quite forgiving.

The Mimosa evo in the green bucket crashed to the ground last week (hence the different bucket from the rest). Transplanted up and it seems she isn't stunted at all. Still keeping up with the other girls.

Aitoflowers three first pistils today.
 
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