"Scientific" Test of Water Wicking Materials

For those of your building any system that uses wicking materials, I have learned quite a bit of experimentation.

Frankly, cotton goes rotten pretty fast.  If you are just starting seeds in a plastic bottle for the near time, an old towel will work.  But after about two weeks, it starts to degrade and it can start to stink.  Also, your seeds roots will actually interlace with the cotton.  That's ok, if they are going into the ground, just plant it with them.  But if you are going past two or three weeks, be aware of the rotting potentials.  

I am building a vertical growing system and need a good water wicking material.  That's where I learned that cotton just does not cut it.

Now to my pseudo-scientific tests of water wicking materials.

Hanging two equal lengths of rope, one composed of poly rope, the other of nylon, I was shocked by the results.  The diameters were 1\2 inch.  The poly rope is a much more "plasticky" rope than the nylon, much rougher too.  It barely wicked any moisture whatsoever.  Byt the nylon acted like it had a pair of lips and a straw!  Wow, I mean I was shocked.  

Maybe I missed something?  Maybe I bought the wrong kind of poly rope?

Right now am I checking the nylon rope, having given up on the poly rope I bought for the test.  Poly rope floats by the way, the nylon sinks, so there appears to be an advantage to nylon all the way round.

Nylon rope is the more expensive of the two, but the dramatically better water wicking ability means you could use thinner diameter rope and save money.  

I want to try parachute cord and rayon, but I don't seem to be able to find that in the hardware store.  

Has anybody else used any of these materials or any others for water wicking? If I can get some of it, I will make a better, more controlled experiment, but at this point, Nylon is THE benchmark for water wicking!    
 

Most nylon rope has a long, loose fiber core (the wick) and a braided outer sheath, the core is what sucks up the liquid and draws it through capillary action, it will do the same with motor oil or any other liquid.

Other rope materials will not perform this function because they are either twisted or braid only, there is nothing that enables them to use capillary action.

Parachute (550 cord) cord is 7 to 9 twised nylon cords in a braided nylon sheath, designed to take sharp jerks of a parachute opening and stopping the fall of an object.  It will not "wick" as well as the nylon cordage above.

Redhawk

I've seen some cool wicking done with above ground containers feeding the roots of trees.
These set ups used nylon rope inside plastic hose.

Thank you Bryant,

I am in the final season of building a three dimensional gardening\farming system for use in a broad range of environments.  Everything from backyards and porches, to growers and farmers.  As such, I want to remove the need for a pump in the system, if possible.  Finding a material that's absorbent and resistant to rot, has proved a challenge.

I tried cotton.  Worked great for about a month- then the system started to smell like a toilet, lol.  Cotton is edible by bacteria it seems.

If you have any other ideas about materials, please do reply with them.  This system is in the final trial stages this Spring and Summer.  As such, I need to make a decision about wicking materials soon, so I can test them in the system.  So far, nylon rope is the clear winner.  However, its biggest drawback is expense.  Was hoping the cheaper poly rope would do.

I hate to toot my own horn, but since I know more about this system than anyone else, here goes.  Frankly, this device could finally take vertical growing from an interesting concept engaged in predominantly by hobbyist and certain avant garde types, to a practical and truly useful system- available to rich and poor alike.  

Because of that, I need all the help I can get.  I hope to work with Mr. Wheaton to offer the first few production units to people on the site, but that's a bit down the line.  But I do know this could change the world.  Any help offered is sincerely appreciated.

Thanks for the insight.

JR

Bryant RedHawk wrote:Most nylon rope has a long, loose fiber core (the wick) and a braided outer sheath, the core is what sucks up the liquid and draws it through capillary action, it will do the same with motor oil or any other liquid.

Other rope materials will not perform this function because they are either twisted or braid only, there is nothing that enables them to use capillary action.

Parachute (550 cord) cord is 7 to 9 twised nylon cords in a braided nylon sheath, designed to take sharp jerks of a parachute opening and stopping the fall of an object.  It will not "wick" as well as the nylon cordage above.

Redhawk

William,

Thanks for the reply. If you know of any other types of wicking materials, please do reply.

Thanks!

JR

William Bronson wrote: I've seen some cool wicking done with above ground containers feeding the roots of trees.
These set ups used nylon rope inside plastic hose.

Hi Jeff. Would you have the brand name or any pics of the nylon rope you used?

Like Hai Le, I would like to have a brand name or better specifications on the nylon "rope" that wicked well.  There are so many and they are expensive so I don't want to have to buy several to get what I really want.  Thanks.

I looked all over and have yet to see a nylon rope that fits the description of the hollow core. Any links would also be lovely.

Bryant RedHawk wrote:
Most nylon rope has a long, loose fiber core (the wick) and a braided outer sheath, the core is what sucks up the liquid and draws it through capillary action, it will do the same with motor oil or any other liquid.

Jaceymae, welcome to the forum!

I don't feel that what Bryant was describing is hollow.

I don't know how well nylon rope sucks up water as I have never used it.  I usually use a cotton rope which for me has always worked well.

Wool might even be good to use as a wicking fiber.  

This wicking material does not need to be a rope.  It can be strips of material or fabric.

The best rope that I have found is a 3/8"braided outer with a white inner core made of some soft sort of synthetic material that looks a lot like cheesecloth under magnification. This kind of rope can be found at the dollar store and is $4.00 for 50' and moves water like a garden hose.

You know a microfibre cloth cut into strips and sewn to the required length works really well... just pull out the sewing machine and do a closezig zag down the cut edges with polyester thread as well, just to control any shedding of synthetic material. This stuff wicks better than anything else I've used.

Nylon actually absorbs water and is great for wicking.
Polypropylene is hydrophobic (repels water) and makes a poor wicking material. It is the ‘floating’ rope
Polyethylene is said to make the best wicking material for SIP’s (Self-Irrigating-Pots/Planters)
Cotton & other natural fibers may wick well, but they’re organic & will rot/stink as they decompose

It can make your head swim; my simple mnemonic is to remember that the plastic containing a woman’s name (Ethyl) is the best for wicking

BTW, Polyester is another commonly used (shorter) name for Polyethylene. So the mnemonic still works, as Ester/Ethyl are both female names (Esther may be a more common spelling for the name)