Wicking Bed Inside Flood & Drain?

[Chi Ma]

Another friend wants me to help set up her AP system. The components are a 3'x6'x7" deep grow bed and a 110 gallon tub. I don't think it is deep enough for root veggies. So I'm thinking of setting some 5 gallon planter buckets  in the grow bed and filling them with coarse sand in hopes that the sand will wick up water and nutrients. What do y'all think about that?

[Sylvia Bernstein]

Sounds like you have a "sprouting" business happening there, Chi.

 

In my experience sand doesn't wick.  Have you looked through the wick bed thread in here?  I bed you could get some good ideas there.

[Chi Ma]

I do have some left over Turface. I'll try that, it's free. I don't know about business because businesses are supposed to make money. The systems I have done required a lil bit of my money. I guess I do it for the love.

Sylvia Bernstein said:

Sounds like you have a "sprouting" business happening there, Chi.

 

In my experience sand doesn't wick.  Have you looked through the wick bed thread in here?  I bed you could get some good ideas there.

[TCLynx]

There has been much talk of incorporating wicking beds into aquaponics.  (Traditional wicking beds have soil/compost in the top layers and a reservoir often filled with coarse gravel or other coarse material below.)

I caution that trying to actually recirculate water through a wicking bed could impose all sorts of variables into a system that could be hard to control or even keep track of.  Anyone doing it should realize they are experimenting and the results might not be what they or anyone else expect (it is hard to know what might leach out of compost and soil into the system water.)

 

Now what you are talking about, Hum.  I don't know if sand would suck water up high enough.  It might work to say, set the roots in the normal bed where they will get the moisture from the high water and then make a little "fence" around them with some material to hold more media as you mound it up over/around the potatoes.  Potatoes only need moisture down at the initial set level and then the new potatoes grow above that.

 

I'm going to have to test using sand for a wicking tray for shoots now sylvia.  I've been starting shoots in trays of compost sitting on capillary matting but sand might be easier to get and I agree it may not wick much, perhaps 1/2-1 inch would stay moist.

[Chi Ma]

TC I will be using some sort of sand or gravel. No compost or anything. I may put some sort if "wick" in the center of the bucket. I have some rock wool blocks laying around.

TCLynx said:

There has been much talk of incorporating wicking beds into aquaponics.  (Traditional wicking beds have soil/compost in the top layers and a reservoir often filled with coarse gravel or other coarse material below.)

I caution that trying to actually recirculate water through a wicking bed could impose all sorts of variables into a system that could be hard to control or even keep track of.  Anyone doing it should realize they are experime I may nting and the results might not be what they or anyone else expect (it is hard to know what might leach out of compost and soil into the system water.)

 

Now what you are talking about, Hum.  I don't know if sand would suck water up high enough.  It might work to say, set the roots in the normal bed where they will get the moisture from the high water and then make a little "fence" around them with some material to hold more media as you mound it up over/around the potatoes.  Potatoes only need moisture down at the initial set level and then the new potatoes grow above that.

 

I'm going to have to test using sand for a wicking tray for shoots now sylvia.  I've been starting shoots in trays of compost sitting on capillary matting but sand might be easier to get and I agree it may not wick much, perhaps 1/2-1 inch would stay moist.

[TCLynx]

Which particular root crops are you interested in?

 

Beets, turnips and onions don't need deep beds.

 

Carrots depending on type might be just fine in shallow beds if they are the half long or short varieties.

 

Potatoes, sweet potatoes, jicama all might benefit from the plant and then mound up gravel around them with a fence later.

 

I'm not sure if using a pot to plant them will really be of much benefit but will be interested to watch your trials to see what you discover for the rest of us.

[Chi Ma]

Probably, radishes, beets and carrots. We will see.

TCLynx said:

Which particular root crops are you interested in?

 

 

[TCLynx]

I'd say plant some of those in the regular bed so you can compare to see which way does better.  Beets and radishes practically grow on the surface as do turnips and onions so there isn't much need for media depth with them.  The carrots will depend on the type of carrot, I usually grow shorter carrots anyway and they have done fine in a 6" deep bed for me in the past.

[Nick Rizzo]

Coconut Coir works, it drain well but still keeps moist and doesn't break down and leach stuff into the water. Take a look at My daughter science project that's what we used for her 10gal system

TCLynx said:

I'd say plant some of those in the regular bed so you can compare to see which way does better.  Beets and radishes practically grow on the surface as do turnips and onions so there isn't much need for media depth with them.  The carrots will depend on the type of carrot, I usually grow shorter carrots anyway and they have done fine in a 6" deep bed for me in the past.

[Sylvia Bernstein]

Hi Nick.  I don't want to rain on anyone's science project - it looks great! - but how long has this been going?  Generally the problem with coir is that it breaks down in a few months.  You generally want a media that won't break down...ever.

[TCLynx]

I have a feeling that if the bed is set up as a wicking bed (gravel or something in the bottom) and the aquaponic water is only added to the bottom layer and not flooded into the coir levels really.  Just letting the coir wick up some moisture as needed, it may work as a wicking bed ok without the rapid break down of the coir as people tend to experience using it as actual flood and drain media.

Of course using it as a wicking bed, you don't get much filtration from the bed.

[Nick Rizzo]

It's been going for a few months and yes coir breaks down but since this project is is for temporary use, we used Gravel and coir on top and the water is more or less dripped into the bed and drains out the bottom. With the few fish we have in there is seems to be working fine. We did add some worms to it as well. After the fair the system will be taken down or used as a seed starter

Sylvia Bernstein said:

Hi Nick.  I don't want to rain on anyone's science project - it looks great! - but how long has this been going?  Generally the problem with coir is that it breaks down in a few months.  You generally want a media that won't break down...ever.