Backyard Aquaponics
A place to discuss aquaponics

Hi Guys,

After reading through some of the threads, i am still a bit confuse about wicking beds.

Based on what i understand currently, water will wick up to 200-300mm in height. Does that mean that the height of the reservoir does not matter as much for it only effect how often i have to top up the wicking bed?

For example, can I have a 150mm depth container? What are the ratio for reservoir to soil?

Am i ok to use a quarter of the depth as reservoir and fill up the rest with soil. Will the surface be constantly too damp?

What future problems am i looking at if the depth is not as high?

Regards

Anyone? You are welcome to share your personal opinions on wicking beds too.

Regards

I don't know if what I'm going to put down here will help you but maybe it can build from here. The way I see it is that wicking beds have several purposes

1. To act as a water storage reservoir
2. To wick water up to the plants.
3. To inhibit weed growth - by keeping the surface of the soil dry.
4. To conserve water.

If you look at some of the better wicking beds you'll see them using milk crates and ground cloth to provide a large space for water storage capacity. The bigger the reservoir space, the less often you'd have to add water. Food and Fish builds good wicking beds and DecalsbyJT has some nice ones in his thread as well. There have been lots of good ones, I can't keep track of them all but there are others.

If you don't provide a decent size reservoir and you don't have an auto top up valve you'll be filling the reservoir way too often.

Personally I wouldn't want a really shallow wicking bed. As a raised bed I think it would dry out too fast on hot days and would be soggy on cold or overcast days. If the bed is too shallow and stays wet too long I think you'll find weeds will grow more easily. They'll be times when it rains and you'll get some but when it's dry the seeds have a hard time germinating. For me this part works well in Summer but not as well in Winter when it rains a lot. In Winter, I get weeds sprouting on paths, in 12" deep rock with no soil .

I would do a few things differently if I were building these again.
1. I would make them smaller - easier to fix leaks and they warm faster in the Spring.
2. I would use a better liner - one of the beds sprang a leak and changing a liner in a 3 x 15 wicking bed probably isn't going to happen any time soon.
3. I wouldn't use rocks for the reservoir - I couldn't find milk crates used and didn't want to pay for any but rocks are a lot of work.
4. My wicking beds rely on ground cloth as the wick and while this works, at some point I envision this breaking down. Putting sand in like DecalsbyJT would have been a better choice and I'll probably have to insert some wicks with sand in the future.

Other than these I'm very happy with how they've turned out and they save me lots of weeding.

Cheers

@scotty435 - Thanks for your reply, i am currently planning on making a smaller version for herbs. Due to my location, i am deciding to make it moveable so i can move it in and out of the hot sun as required. Hence i am looking at a plastic planter box as attached. The problem is it has a standard depth. Hence my question about the golden ratio of reservoir to soil.

Regards

In the system I'm building ATM most of the beds will be wicking beds, but with 20mm river gravel as a media rather than cavities, and they will flood and drain just like the grow beds in my other system. I've emptied a big load gravel from the trailer today (~800kg), and not quite filled the first bed, a 1000 round trough- only 3 more of them, and 20 X 600l rectangular beds to go!
I'm planning to generally put about 100mm of dirt & hay over the geotextile, on top of the gravel.

I put soil over the top of the geo-textile on my system, perhaps as Gordon is doing, and it does work quite well. Here's a link to what I did - http://www.backyardaquaponics.com/forum/viewtopic.php?f=18&t=13622&hilit=bucket

The bed showing the liner and rocks during the build is one of my smaller ones.

Part of the reason for suggesting rocks not be used is the work involved in removing them if the liner springs a leak. With using milk crates that's less of a problem although you still need some rocks or sand as filler and the sand aids the wick better than the rocks. Then you'd still have to remove the soil as well so it's not easy either way. With a planter that size using rocks would be a non issue.

Can't say I think the containers will work much better than just using them as planter, have you considered using shade cloth instead of moving the plants, then just using larger containers that could be moved with a 2 wheel dolly?

@Gunagulla - Just double checking that you are using 20mm reservoir and 100mm soil mix, not CM? What is the total height of your wicking beds? Do you mind sharing how you are plumbing it to flow and ebb? Is there a thread with pictures?

@scotty435 - I have thought of it too, but i am still worried about the heat even without the direct sunlight, where i am, weather report at 10am shows 31'C and 70.5% humidity.

Regards

Using 20mm river gravel, and that will be about 20cm deep in the rectangular beds, and ~40cm deep in the round beds for the trees, where the soil will be a bit deeper.

@Gunagulla - Thanks for the reply, what is the ratio of soil to gravel? Lest take example of your 20mm gravel bed, it has a 20 cm height as reservoir for the water, what is the soil depth?

@Anyone - What are the types of herbs that you guys manage to plant successfully under tropical weather conditions with high humidity and mid-high 30s 'C in the afternoon and hot sun?

Regards

~10cm of soil/hay on top of the geotextile, on top of 20cm gravel so a ratio of about 1 soil to 2 gravel for the 30cm deep rectangular beds, and similar in the 60cm deep round beds, which will have deeper soil for fruit trees. I'll use a 14-20mm gravel mix, for which I've just found a good price locally.

@Gunna... your comments likely answered my question about what you are doing with all that rock..

@Curious.. I find it frustrating that people come up with terms that make it sound like they have devised something special.. and revolutionary.. umm.. Wicking Beds

Interesting that you present a photo of a Self-Watering Pot or a Water-Well Pot and they are nothing more than Wicking Pots.. or small wicking beds...



Some fool threw six of these out some weeks back, and you can see what I have done with them..
Just drilled through the base and using Gorilla Glue, sealed a riser tube to the base, and then added Agri-Fabric and filed with dirt..
I had thought to add stone under the base, but thought it safer to have nothing...

The plan is to set them up side-by-side and run a gutter under the middle section under the overflow holes in the side..

Then I will have small hoses from above, sitting in the riser tubes..
They will flood and overflow each cycle of the AP Flood and Drain,
and like Gordon, I plan to have larger tubs (old Washing-Machine outer bowls), but instead of using rocks, I was thinking of Bio Balls, IF I can get them cheaply, and then Agri-Fab on top and soil over that..

The existing planters (shown) - have Hoan Ngoc growing there in - "Gift of the Gods"

The Bowls will have fruit trees...

and then I hope to make some more, like GG's, for root vegetables...
..
.

@Gunagulla - Thanks, I might just go ahead and give my micro wicking bead a try using your ratio one some free time comes around. will post my findings.

@BuiDoi - Thanks for sharing

@Anyone - If any other members had experimented with a micro wicking bed please share your experience, thanks in advance.

Regards

Link is in my sig, pics will appear as it progresses.

GG... a foolish comment like I always make...

What good the 2:1 ratio.. What difference if it was 10:1..

I would have thought you would have said 10cm of gravel and 20cm of grow-bed media..

All you want is for the water during flood to touch the wicking bed media, and wet it..

Surely, the only benefit of 20cm of gravel, is the bacterial potential of all the gravel, and the actual wicking bed won't even know there is rock there..

So in my case, with the silly pots, there is about 30mm of void under the mediaand about 120mm of media, and periodically , it will overflow, wetting the media..
..
.

If it was 10:1, that would be 27mm of dirt on top of 270mm of gravel- hardly enough to support any plants, since they will probably only put fine roots through the geotextile, not any large tap roots.

I want sufficient volume of GB media, ie gravel, for enough surface area for the bacteria to colonise, otherwise I'd need even more beds, and I dont have the space for that without major earthworks, and expense- it's costing enough already!
I'd prefer to operate this with minimal to none of that external filtration malarchy if possible!
That said, I will probably use a 135litre barrel as a distribution manifold from the SLO, and I may use that to filter out a few solids to start with, as I probably wont be cycled by the time I get the fish.