I was having a conversation with @Skiball about hempy buckets and how they sometimes utilize capilary action to suck up the nutes from the reservoir at the bottom, said he. I was saying i do not think that capilary applies to inert media like perlite, hydroton or plastic (MBBR) but i wanna know what you guys think about this… Does it or not?
There is obviously no argument with rockwool, or maybe coco, right? But perlite or hydroton?
Is i don’t know an acceptable answer? 
Of course, any answer is acceptable. Would you dare speculate tho?
It’s not about being inert but about it being porous. I’ll think of a good example in a sec.
I think i see where you’re going with this… YES.
You’re right.
It’s about porosities in the material, for example the pellets that your plastic bit are made from absorb water right out of the air. So much so that the pellets (nibs) must be heat treated to obtain a -40° f dew point otherwise the resulting steam blows up in the injection barrel there is plenty of capillary action
HAHAHAHAHAHAHA
Would you run that by me again!?
I would think capillary action would be negligible in rock, plastic and such.
Capillary action (sometimes capillarity, capillary motion, capillary effect, or wicking) is the ability of a liquid to flow in narrow spaces without the assistance of, or even in opposition to, external forces like gravity. The effect can be seen in the drawing up of liquids between the hair of a paint-brush, in a thin tube, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid.[1]
Read it man! Nice. I am gonna read about cohesion now.
Cohesion (from Latin cohaerere “stick or stay together”) or cohesive attraction or cohesive force is the action or property of like molecules sticking together, being mutually attractive. It is an intrinsic property of a substance that is caused by the shape and structure of its molecules, which makes the distribution of orbiting electrons irregular when molecules get close to one another, creating electrical attraction that can maintain a microscopic structure such as a water drop. In other words, cohesion allows for surface tension, creating a “solid-like” state upon which light-weight or low-density materials can be placed.
Mercury exhibits more cohesion than adhesion with glass.
Water, for example, is strongly cohesive as each molecule may make four hydrogen bonds to other water molecules in a tetrahedral configuration. This results in a relatively strong Coulomb force between molecules. In simple terms, the polarity (state of which a molecule is oppositely charged on its poles) of water molecules allows them to be attracted towards each other. The polarity is due to the electronegativity of the atom of oxygen; oxygen is more electronegative than the atoms of hydrogen, so the electrons they share through the covalent bonds are more often close to oxygen rather than hydrogen. These are called polar covalent bonds, covalent bonds between atoms that thus become oppositely charged.[1] In the case of a water molecule, the hydrogen atoms carry positive charges while the oxygen atom has a negative charge. This charge polarization within the molecule allows it to align with adjacent molecules through strong intermolecular hydrogen bonding, rendering the bulk liquid cohesive. Van der Waals gases such as methane, however, have weak cohesion due only to van der Waals forces that operate by induced polarity in non-polar molecules.
Cohesion, along with adhesion (attraction between unlike molecules), helps explain phenomena such as meniscus, surface tension and capillary action.
Good reading man!
i love when it gets scientific like this reminds me in my old days in the university study chemical engineering
Like I said it might work with the bio balls are small enough. On the flip side even if they are the honey combs would need to line up or there’d be dry spots.
I think there is a simple way to test this. Just pile some of the medium you want to test on a plate or a shallow bowl. Add a small amount of water but do not poor it on top. You want to keep the top dry. Then wait to see if any part of the medium material gets wet after a while. If any portion thats above the water line is wet, then you have some wicking/capilary action going on. The higher the wet line is above the water level, the more wicking action you have.
Actually a better way might be to put some water in the bottom of a tall skinny glass. Then add your medium to well above the water line and watch to see if there is wicking.
Yeah right! Alex Trebek won’t like the idea!
Hey @MadScientist I was going to comment on your other thread about the plastic thingies. This is the specific issue I saw with using them.
You don’t need capillary action for hydroponic media in general, but I think the way that a hempy bucket works you need some media that will wick (capillary action). They are usually set up with perlite or vermiculite right? Both those media will transport nutrient from the reservoir in the bottom of the bucket.
Hey Captain @RickSanchez ! What do you think of what i am doing right now, watering by hand until the roots reach the bottom of the bucket. Then i won’t have to worry! I think…
Perlite most definitely wicks just fine. People use it with fabric pots to make a Sub Irrigated Planter (SIP). Lava rock also has this property. As stated, it’s about the porosity.
In a hempy you need the media to draw the nutrient water up to the roots. If you have media that doesn’t wick the roots above the water level won’t get any.
You could try an experiment. Fill two hempy buckets, one with perlite, one with the plastic you are thinking about using. Weigh them dry and water them with the same amount of water each. Then let them drain and weigh them again. That would tell you how much water they can hold compared to one another.
Someone correct me if I’m wrong , but my understanding of the hempy bucket system is that it is a wicking system; a bucket with a drain hole in the side filled with vermiculite or perlite or a mix of the two.
I think it could work with coir or even rockwool croutons. It could work with plastic as well, but the plastic would have to have a conformation that allowed it to wick.
