Small wicking box experiment

Learn what a wicking box is  in this recent thread:
https://squarefoot.forumotion.com/t16952-compost-tea-with-wicking-beds

For this experiment I used an empty 40 LB. kitty litter bucket, a scrap piece of plexiglas, and some silicone caulk.

From top to bottom: MM, muslin, rocks from my driveway (including fir needles).

The MM is well saturated. You can't see it in the pic, but the water level in the gravel is right at the muslin.

I transplanted a couple of chard seedlings, and put the bucket under lights with some other plants.


Theoretically, I should only have to add water through the filler tube (the gray PVC pipe) when the water level in the gravel drops down to near the bottom.

Will it work?   Beats me!

Nice! I like that you don't faff around when you have a question on your mind. DO you have a time frame for your experiment?

I guess it will be over when I need the chard for dinner!   

boffer wrote:
Theoretically, I should only have to add water through the filler tube (the gray PVC pipe) when the water level in the gravel drops down to near the bottom.

Boffer - I have been following the thread you referenced but if you let the water level drop down to near the bottom, how will the water "wick" up to the MM.  Does the gravel act as a wicking agent to wick the water up from the bottom to the MM.  Do rocks wick water ???  Don't you need something like a wicking basket or panty hose or something that goes down into the bottom to wick the water up to the muslin and then the MM.

Yolos, that's exactly why I'm trying this!  I don't get it either!  I don't understand how dry MM will create the capillary action to pull the water up the rocks.  

I followed some of tumtumsback's links from the other thread, and there seems to be a number of folks doing it this way, but I'm still    !!

I thought there had to be spots* of MM that dip down into the water, then an air space between the water and the rest of the MM.  Plus an overflow at the max level of the water.  *I've seen pics of Yolos cup perforated and set about into a solid frame like the bottom of the top tub or top flower pot.  These would be the MM wicks.  the link was just a schematic I quickly grabbed.

http://e3living.com/wicky-grower-20-gallon-4-pack/?utm_source=shopzilla&utm_medium=shopping&utm_campaign=products

Thank you yolos and sanderson for speaking up and letting me know that I'm not the only one saying 'huh?'!

If my experiment works, we still won't understand why, but we might become believers!  

Thanks Boffer for this experiment. I been looking at this idea. we're all watching.

has55, I'll throw this out for your consideration.

At this point in time, if the rock filled tub works, as far as I can tell the main differences between it and a water filled tub using 'baskets' are these:

Rock filled tub

• +only need to have one box
  
• +easier to make (no divider or baskets)
  
• -tub holds a lot less water
  

'Baskets' into tub

• +much greater volume of tub water=less frequent  water addition
  
• -more work to build (divider and baskets)
  

Two suggestions for either method, based on my experience:

Even in my comparatively cooler climate, several inches of mulch reduces water usage.

If you're doing an experiment, going cheap is OK.  But if you want to build a box, say a 4x4, that is intended to perform without fussing or fixing, spend the money on a proper tub liner such as 30-40 mil shower pan liner or pond liner, or roofing EPDM.

Hahahaha wow, this is so awesome :)I'm super glad that I've just shown up on board the other week and already creating some inspiration!

Boffer, you waste no time   I will definitely be keeping an eye on the progress... Basically, I don't truly understand the wicking action either, but according to some, "...water likes to go wherever it's not, even if that means going up..."

If you drop your cell phone in water, an easy fix to save its life is to throw it in a box of rice... The rice never actually makes direct contact with the innards of the phone, or the water molecules on the silicon chip board, but because the rice is hygroscopic (a substence which tends to absorb moisture from the air), it acts as a desiccant (a hygroscopic substance used as a drying agent.) I feel that in the case of the wicking bed, the soil is the hygroscopic desiccant and being that its sitting on top of a huge pool of water/moisture, it has no choice but to naturally wick up the moisture (even without direct contact to the water). I've also read that water can wick up through about 18 inches of vertical soil!? Being that my MM is only going to be 6 inches, I feel that this should be no problem.


Definitely staying tuned in on this one  

tumtumsback wrote:Hahahaha wow, this is so awesome :)I'm super glad that I've just shown up on board the other week and already creating some inspiration!...

There's no denying that the unbridled enthusiasm of new gardeners is contagious! Especially this time of year when those of us in 4 season climates are starting to chomp at the bit to do something besides reading seed catalogs!

tumtumsback wrote:...it acts as a desiccant (a hygroscopic substance used as a drying agent...

   That could be the principle.  Off the top of my head, aren't desiccants generally used inside of relatively closed environments?  Inside of a plastic bag, or a small space like a gun safe, where the air doesn't change much.  I understand the reason to have a tub overflow method (in your case, the pipe), but won't that  keep the humidity equalized above and below the MM?  

I didn't provide for an overflow method since I can see the water level in the tub, so that  should create a closed system where the desiccant effect might work better.

After 24 hours, the water level has dropped 1¾ inches.  (Yes, I did double check for leaks!) Maybe the system is just stabilizing, or maybe the MM wasn't as saturated as I thought?  Interesting!  

Bof, do you have a moisture meter for measuring the MM?

I do, but I've never trusted it. It seems to work properly in our ornamental garden soil (native dirt plus compost), but it seems to give erroneous readings in MM.

boffer wrote:Yolos, that's exactly why I'm trying this!  I don't get it either!  I don't understand how dry MM will create the capillary action to pull the water up the rocks.  

I followed some of tumtumsback's links from the other thread, and there seems to be a number of folks doing it this way, but I'm still    !!

Some material will bring water up from a lower level by osmosis and then capillary action take over   Look up the definition of it .
If I remember correctly it runs something like...... it is the movement of a liquid or solution through a semi permeable membrane to a weaker or stronger one . MM being damp but able to hold much more liquid could well attract it off the stones and actually have a pulling effect once it is an established moisture path .

 When my home got flooded due to a hidden leak in the central heating system that uses pumped  hot water in radiators it took several years for it to show up.

 When it showed we were out , the 6 inch thick floor slab of concrete cast inside a water proof membrane had become saturated and on a warm day the dew point had been reached . the water wicked up through the carpets , made the humidity so high that other things began to happen , the water went up all the internal walls as there was no damp course in the base of them.
 The osmosis had turned into capillary action by the time we returned home  24 hrs. later,  the water had soaked up the walls to just over five feet high . .....  happy times lay ahead .

boffer wrote:I do, but I've never trusted it.  It seems to work properly in our ornamental garden soil (native dirt plus compost), but it seems to give erroneous readings in MM.

You have to keep the probe scrupulously clean if it is a bi metal lone like mine  , copper for most of  the rod and some light grey dissimilar metal ( zinc ??? )  on the very tip.

Any tarnish on the copper or tip  part of the probe will act as an insulator and  will not make the battery effect the meter needs to move the needle ( galvic current ) when both of the metals are inserted into moist acid or alkaline soils.

 I use a hard nylon green " Scotch-brite "  pan scrubber and a drop of rain water to clean mine each time before In use it & then dry it on a bit of soft clean cloth .Each time I use it in a session I use the cloth to wipe the probe again to prevent false readings.

Following is a website that goes into the whys and wherefores of the wicking beds.  Some of it goes in depth into how things work.  But I did not understand half of it.  Give it a look see.  It is written by a guy named Colin Austin who I have heard mentioned by a few of the Australians making these or similar beds.

http://www.waterright.com.au/wicking_bed.htm

Plantoid, thanks for the info on the wicking, but esp the probe. It explains past failure/false readings. I just quit using them, even though I kept it in storage. The internet wasn't around or in it's birthing process for quick solutions.
Thank you again.

Yolos, interesting find.   At various times, he's used wicking beds as water storage in areas of intermittent drought, as a means to create healthy soil from barren dirt, and to remove CO₂ from the atmosphere.  He tends to go off on tangents from the topic titles, which makes it hard to find answers.

Interestingly, he recommends using organic matter rather than stones in the 'tub'.  He feels that the anaerobic decomposition creates a tea that is full of fungi that benefits the soil.  There was no research data provided to support his opinion.  

The more I learn, the more I learn how much more I don't know!    

boffer wrote:

The more I learn, the more I learn how much more I don't know!    

Yup.   

boffer wrote:Yolos, interesting find.   At various times, he's used wicking beds as water storage in areas of intermittent drought, as a means to create healthy soil from barren dirt, and to remove CO₂ from the atmosphere.  He tends to go off on tangents from the topic titles, which makes it hard to find answers.

Interestingly, he recommends using organic matter rather than stones in the 'tub'.  He feels that the anaerobic decomposition creates a tea that is full of fungi that benefits the soil.  There was no research data provided to support his opinion.  

The more I learn, the more I learn how much more I don't know!    

The problem with using the organic matter as the wick is that it can bring the water up too high and it will cause the plants  hair roots & tap roots to rot . You have to do some careful experimenting with your growth medium & the water levels as not all plants like their " feet "  in too wet a ground .


In fact it seems most plants like it a tad towards the dry side then a decent wetting and drying off a bit.. This might be something to do with the plant cell walls getting stressed and therefore becoming stronger and more self supporting of the plant.

One Week Update:

The chard plants are looking healthy.


On the second day, the water level dropped to 2 inches, and has stayed there since.  The surface of the  MM is beginning to dry out.


I didn't expect to see the roots growing through the muslin to reach water.

hey Boffer this is pretty neat!

reminds me of hydroponics.....  

I look forward to see how this goes.....I hope you have enough winter veggies to eat so you don't consume the project   

happy gardening
rose

Boffer, thanks again for sharing this experiment. 

I see the roots have penetrated that muslin -- I'm thinking muslin might be woven loosely enough to the point of easy penetration for a root. Do you think if you used a tighter burlap, or even something like weed fabric, you may not have had that problem? Do you have any worries of root rot?

It looks like this experiment is going somewhat well though. Would you say the bottom 50% of the soil is moist? Bottom 60%? 70%? Or in other words, how much percent of the top soil is dry -- the top 20%, 30%, 40%? And have you been going back over the top and adding any water?

Regarding planting different crops in wicking boxes, a few considerations:

Roots will always seek water, so if the water is not in the growing medium, often the roots will go to the water.

Some plants have deep root systems, some have quite shallow root systems. If the top portion of the growing medium is going to be dry, the plants with the shallow roots may suffer.