Coconut fibre as grow bed medium

[DaveOponic]

I'm building a new system with 1000 litre plastic tank. My first growbed will be made from a 16' piece of 220 cm diameter PVC stormwater pipe that I got for free. I am almost done building stands for the pipe from angle iron and 5/16" galv. bolts.

Now I need to decide what to fill the pipe with. There is a heap of left over blue metal next door but it will be heavy and hard work loading and filling, washing etc.

I am thinking of using coconut fibre and have already bought 6 huge bags of coconut husks (50 cents a bag) from a nearby kedai (roadstall) that sells fresh grated coconut (for curries - nasi lemak)

Coconut fibre is usually sold here for people who grow orchids. they use charcoal and coconut husks in a cone shaped wire mesh hanger.

Has anyone used coconut fibre as a growbed medium?

Are there any drawbacks in using it in a flood and drain system?

I reckon the pipe will be easier to empty and clean than a gravel medium as the fibre is light and doesn't seem to break up.

I am thinking of just packing the husks into the pipe as they are ( half and quarter shells) as this will save a lot of cutting and also leave a lot of air pockets in the pipe.

Any tips/suggestions?

Dave

[DaveOponic]

Just read this article on coconut fibre - coir. It seems to confirm what I have already read about coir. Luckily I have a ready supply at a cheap price. I should be able to fill my drain pipe with these used coconuts for under
$ 10.00. and my grow bed won't be weighed down with gravel.

I have already been testing a flowerpot full of the coco fibre under the outlet of my pond system. Water runs through the fibres nicely and doesn't get water logged but manages to retain more moisture when the water is off than the clay balls which dry out when the pump switches off.

I will try and post some pictures this week.


http://www.progressive-growth.com/article-coco-coir.php

[Murray]

Hi Dave,
About two years ago I ran a 585 ltr grow bed filled with coco peat (coconut fibre) As a grow medium it worked very well. Some of the things I found were that it worked better when it was flooded only once a day which did not fit in too well with the rest of my system.
Also it made the water very dirty, like very strong coffee. The fish did not mind, but half of the fun in Aquaponics is watching the fish.
Eventually I ran the bed independently of the rest of the system. I watered it daily with a watering can of water from the fish tank. It got just 2 ltrs of water a day. Coco peat holds moisture very well.
I grew carrots, potatoes, beetroot root crops as well as the usual lettuce, silverbeet and the like.
Eventually I tired of it and repalced it with gravel and hooked the bed back into the system.
Altogether I ran the bed for about 9 months.

[djs-sa]

run to waste is the method to be using with coco coir it u water too much u will get rot problems due to excess water

[Hamish]

I use coco coir in my bottom 2 beds. I have them plumbed up to the pump line that feeds the top flood and drain beds. I have a grid of 19mm poly with holes punched in it burried just under the surface of the coco beds. I have an inline filter to keep solids out of the poly grid so the holes dont clog. Once every couple of days I turn the tap on to water the beds with the fish tank water. Only need to leave it on for about 30 seconds untill water starts to trickle out of the drain. I have a plastic container under the drain to cach the water that trickles out and I then use this to put back into the bed over the coming days and water other plants in pots untill the water finally runs out - then I turn the tap on for another 30 seconds and start the cycle all over again. Means I have to top up the fish tank water a little more frequently but not that often as the coco coir beds use such little water after their initial soaking. One thing though - the coco coir available here is ground up quite fine like fine bark chips - sounds like yours is a lot coarser.

[Murray]

Actually you don't get rot problems. No evidence of rot problems in 9 months anyway, and 6 months of that was flood and drain on a 45 minute cycle.
When I did the test both Gary and I thought that rot and waterloging would be a problem....but they were not.
What actually brought the trial to an end was salt in the system.
I had a bad case of ICH in my fish tank brought in with some new fingerlings. I dosed the fish tank heavily with salt to deal with the ICH and the salt got into the coco peat and wrecked it.
Apart from the very bad discolouration of the water the coco peat worked very well.

[fishfood]

Coco fibre seems like vemiculite i have been running that for 2 years on 15 min on 2 hrs off current crops corrots [just emerging ] onion [brown and white ] cabbage and tomato Notable has had great success with it also

[DaveOponic]

the coco coir available here is ground up quite fine like fine bark chips - sounds like yours is a lot coarser.

Hamish

Yes I have bought the coconut outer layer. They are chopped in half or quartered. I am soaking them in a big plastic bin at present. No sign of coffee coloured water Murray but thanks for the warning, I like to see my fish in clear water if possible.

I will trial the big pipe of coconuts and see how it goes. Everything is changeable here as we are probably only in Borneo for another two years and then back to Qld. Using cheap local materials is preferable and I like the fact that the fibres are light.

Being relatively fresh coconuts the fibres may last a couple of years.
I plan to make the end caps detachable for easy cleaning.

Dave

[djs-sa]

comes back to climate i spose as colder it is longer to dry out completely???

[Hamish]

You might have to crush up the shells a bit?