Coastview Aquaponics seeding technique

[Chris Smith]

Until recently all the work at Coastview Aquaponics has done by our family. Our farm has grown in size and has evolved over the last year. We have improved on the efficiency of our day to day work to save us labor/time. During the evolution of our farm we have constantly been improving on techniques that we have learned. One of our improved techniques is our new seeding process. We have been using this new seeding technique since October 2010 and it has proven itself well over multiple harvests. Now that this technique has proven its self we think it is time to share.

 We used to use a coconut & vermiculite mix in 2" net pots that were placed into 32 cell starter trays. This worked OK for us but we had a poor overall sprouting rate. Sometimes the seeds would sprout then die once touching the coir.  Sometimes we would have a bad block that would not sprout anything at all. We later learned the coconut was imported from overseas.

 

Here is an example of poor germination with coir mix. Every cell was planted at the same time and only some of them came up.

 

 

 

 

 

 

 

 

 

 

We began experimenting with alternative medium for seed sprouting. We tried many different mediums and had the best success with black volcanic cinder. This medium is local produced and readily available when living on an active volcano.

Black volcanic cinder is as light as hydroton if not lighter. Lots of it will float if filly flooded. Cinder is very porous and has more surface area than standard gravel. It has excellent wicking capacity in 2" net pots. The cinder is very easy to recycle and use again.

The cinder from the quarry is very dirty with lots of fine material mixed in with it. We screen and wash it to size grade and to remove the sand and silt. The larger cinder is used for gravel beds and the small cinder is used for seeding. The sand/silt is used in our wicking bed medium.

We now use our newly developed technique of seeding net pots directly into our sprouting rafts(2'x2'w/ 61 holes) using cinder as the sprouting medium. We line up 4 rafts at a time, insert net pots, then pour the cinder over tho top of the rafts. Using a small hand broom we broom the cinder into all the net pots and then broom off the excess.We are able to fill 4 rafts(244 net pots) with media in less than 10 minutes.

 Previously we seeded net pots in sprouting trays that would be later transferred into the same rafts after 7-10 days. We now eliminate the labor of transferring from sprouting tray to raft which saves us hours a week. We have shifted away from pelleted seed to using conventional seed(mostly grown by us). Raw seed tends to fall into the voids in the cinder to a perfect depth. The cinder has a wicking capability and if the bottom of the net pot is sitting in water then the seed on top will have adequate moisture for germination without rotting issues. The roots of the plants have all the oxygen they need in the voids of the cinder and grow very quickly.

 

Seeds germinating out of direct sunlight. I cover with plastic to keep them from drying out. After a 3 day germ I move them to one of the sprouting tables.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

We germinate the seeds our of direct sunlight for 3 days. By then the first seeds are looking for sun and I move them out to the seeding tables. We made custom seeding tables so that they would hold 8 sprouting rafts at 2'x2'. The tables have a constant 1" of water flowing through to provide fresh nutrients to the seedlings. These tables are like a thick NTF table. After two weeks the roots are long enough to need more water and we move the rafts to the nurcedry trough to make way for the next batch of seedlings.

 

These rafts are floating on 1" of water in custom sprouting tables. This table is a thick NTF table. The sprouts stay here for 2 weeks. We have 2 of these tables.

 

 

 

 

 

 

 

 

 

 

 

 

Here is out nursery trough. The plants grow in here for 2 additional weeks. They then move to the grow out troughs and get spread out to a grow out spacing.

[Jovan Johnson]

Hi all

I am fairly new to this technology, however i have done tons of reading and i am writing a business plan for a system similar to the one at green acre organics(u should check out their germination system  http://www.youtube.com/watch?v=CB2hh-9NpPI )

would fine wood dis be compatible, since it holds moisture and clings together so it wont fall through the holes and its organic if u use shavings from untreated wood?

eagerly awaiting your response 
Jovan

[Chris Smith]

I used to use the same method of germination as Friendly and Green Acres. I would get mixed germination rates with coconut coir. Sometimes a particular block of coir would be tainted with something and nothing would sprout. If I loose a weeks worth of planting form bad media I will loose a weeks income 6 weeks later. I later learned that the coir was imported for overseas which I have a problem with. I now use volcanic cinder that is being created on this island as I write this. I am trying to use as much local supplies as possible.

I have never tried wood as a planting media. It might tend to rot after a while. Any media that clings together too much may not let enough oxygen to the roots causing poor germination and growth. You will want to experiment with it and see how it works. It will be important to use untreated wood! You will need to know the exact source so you sure there are NO contaminates. You will also want to check the pH to be sure its not excessively high or low which will affect the germination.

 

 

 

[Jovan Johnson]

Thanks for your input Chris
Cone to think of it, oxygen levels would become a problem as when moist it will stick together, so like anything else in life a balance is what is desired. The problem is that I am in Jamaica i cannot get the cinder and importing it would be a no no, because it will be counter productive and only contribute to the worlds existing problems. In Mr. Halllan's video he grew the seedlings in a medium that looked like perilite and rinsed it off the roots and planted after. the problem is that if you are operating a small backyard system them no problem however if it is a bigger one as i want to operate then labour cost will become a problem. So i am officially stuck :) . Any suggestions?

[Harold Sukhbir]

Hi Jovan,

I am aware that in Jamaica you have an abundance of coconut husk as a natural source. The dry shredded husk from trees inland from the coast are suitable. I've found the coast husk has a higher PH and salt content than the ones around my neighborhood. I crush and shred the husk, rinsing several times, i usually get a PH of around 6-7 and get rid of the salt and other general impurities this way. At the garden shops its sold in blocks ( from Sri Lanka ) at about 5-6 USD and can fill around 200 net pots. I usually reuse the husk for up to three grow-outs. I also used pea gravel( quartz ) which works well but requires more wetting cycles but is very expensive/heavy.

[Nigel Clement]

Can anyone point me in the right direction to obtain the trays you can place 2" and 3" net pots in for nursery purposes. Hopefully its available online. I'm probably searching using the wrong name.

[Chris Smith]

The trays are 32 cell plug trays. They come with square and round cells. I got them at a local greenhouse supply store by the case.

I used those trays for a long time until I got tired of transerring the net pots to rafts once the seeds had germinated. Now I seed net pots direct in rafts which saves me hours of labor a week by not having to do all the transferring. If you use this method you do not have to find trays just get the foam for your rafts and drill some of the cut down sheets to very close spacing like the plug trays have. For seeding rafts I use a 2 inch spacing and get 61 holes in a 2 foot by 2 foot square.

[Nigel Clement]

AHhhhhhh, Chris thanks! Geez, clearly I wasn't paying full attention. By the way......nobody warned me about the addictiveness of aquaponics!

Chris Smith said:

The trays are 32 cell plug trays. They come with square and round cells. I got them at a local greenhouse supply store by the case.

I used those trays for a long time until I got tired of transerring the net pots to rafts once the seeds had germinated. Now I seed net pots direct in rafts which saves me hours of labor a week by not having to do all the transferring. If you use this method you do not have to find trays just get the foam for your rafts and drill some of the cut down sheets to very close spacing like the plug trays have. For seeding rafts I use a 2 inch spacing and get 61 holes in a 2 foot by 2 foot square.

[Jovan Johnson]

Hey Mr. Sukhbir

Thanks for the advice, and there is really an abundance of coconut husks here in Jamaica. I have one more question, how do you shred the husks, so u use a machine or is there another way of doing so? and do you soak before or after you shred?

Yours Truly 

Jovan

Harold Sukhbir said:

Hi Jovan,

I am aware that in Jamaica you have an abundance of coconut husk as a natural source. The dry shredded husk from trees inland from the coast are suitable. I've found the coast husk has a higher PH and salt content than the ones around my neighborhood. I crush and shred the husk, rinsing several times, i usually get a PH of around 6-7 and get rid of the salt and other general impurities this way. At the garden shops its sold in blocks ( from Sri Lanka ) at about 5-6 USD and can fill around 200 net pots. I usually reuse the husk for up to three grow-outs. I also used pea gravel( quartz ) which works well but requires more wetting cycles but is very expensive/heavy.

[Jovan Johnson]

I also have another question, could i use the coir instead of hydroton in the net pot sitting in the rafts?

Harold Sukhbir said:

Hi Jovan,

I am aware that in Jamaica you have an abundance of coconut husk as a natural source. The dry shredded husk from trees inland from the coast are suitable. I've found the coast husk has a higher PH and salt content than the ones around my neighborhood. I crush and shred the husk, rinsing several times, i usually get a PH of around 6-7 and get rid of the salt and other general impurities this way. At the garden shops its sold in blocks ( from Sri Lanka ) at about 5-6 USD and can fill around 200 net pots. I usually reuse the husk for up to three grow-outs. I also used pea gravel( quartz ) which works well but requires more wetting cycles but is very expensive/heavy.

[Chris Smith]

Yes coconut coir can be used in the net pots. The Friendly technique uses 70% coir and 30% vermiculite. Friendly now prefers course coir because it allows more oxygen to the roots and gets less soggy.

 

[Harold Sukhbir]

Hi Jovan,

I use the husk which are shredded into small 1/4"- 1/2" squares, these are bought in 1 ft square blocks. I use the to germinate and for full grow-out.I rinse them a few times and soak overnight to remove any thing unwanted.  I tried the coir but they gave me about 30% germination success(way too much moisture). With the husk I'm up to a 95% rate and the 5% failure may be due to seedlings that are off. Initially i gathered the shells, cut, pounded, and stripped them manually, but the store bought product was low in cost, that's the reason i switched. However if you're thinking along commercial lines, husk being a recurrent expenditure, you may want to consider using something more sustainable like Hydroton, pea gravel, expanded clay etc. You can read more here http://aquaponicscommunity.com/forum/categories/media-topics/listFo...    

 

[Jovan Johnson]

ok thanks again, you people have an abundance of knowledge flying around :)  This is like the FACEBOOK OF AQUAPONICS. one last thing do i neeed to have the husks shredded to the level of coffee grounds or is the hand shredded consistency ok?

THANKS AGAIN!!!!!!  

Chris Smith said:

Yes coconut coir can be used in the net pots. The Friendly technique uses 70% coir and 30% vermiculite. Friendly now prefers course coir because it allows more oxygen to the roots and gets less soggy.