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.

[Chris Smith]

Harold, I found he same that you have. Coconut husk that is too moist we can cause root rot. Cinder or other porous media will wick moisture keeping seeds moist while also providing adequate oxygen for root growth. I am fortunate to have such a good locally available media! I am thankful for where I live every day!!!!

Harold Sukhbir said:

Hi Nigel,

Looks like Chris is one up on us here. If i were to have constant water flowing into my coconut husk of seedlings they will rot for sure.The cinder wicks while the husk retains water. Chris is using the ideal media for his raft(availability,cost,use etc). Makes me want to pack up and go to Aloha land!!!

Nigel Clement said:

In response to Averan's point, I have read that there is also the possibility of the moisture being too much for the young roots from the sprouted seeds ultimately leading to them rotting.

[David Waite]

Chris like it or not you are blazing a trail for commercial growers and the hobbyist like myself. We really appreciate the details. In this infant industry the commercial growers like your system, Friendlys and the babes in Florida will make all of  us better growers only if we share info. There will be a time when a hobbyist like myself or Averan will have an idea that will work better for you to. Mucho thanks. Last question do you have any air  in your seedling troughs.

[Sahib Punjabi]

:-)

Chris Smith said:

My current seeding operation has gone through quite an evolution over the last couple of years. I am constantly trying to improve on the process. I am posting what works for me right now. I may come up with a better idea next week which will take months to provide data on and make me comfortable to post to the community. I do not post anything that I have not actually tried and proven to work in my systems. I am just trying to save you the learning curve that I went through! If you do not think my techniques are good, please show me something better (that you have proven by actually doing it) and report back!!

Averan said:

Thanks David....I had not missed his point at all and fully understand why it was necessary for him to take the approach he did.  My point was that there may be other situations/layouts where my suggestion would work better.  A raft of seedlings is going to take up space somewhere.  And it is going to use sunlight and water.  Instead of building an entirely separate structure in its own area with its own plumbing to deal with, one could simply dedicate a portion of their growing troughs to seedlings.  Germinate your pots somewhere else first like Chris does, then put the fully sprouted seedling raft in the trough.

Nigel, if that were true, then Chris' technique would not work:  "The tables have a constant 1" of water flowing through to provide fresh nutrients to the seedlings."  1 inch or 12 inches, the depth doesn't matter to a seedling.

[Averan]

Actually Chris, I think you're doing great work for us all and really appreciate it.  I was not criticizing your approach or work in any way.  And thank you for the confirmation and clarification!  =)

[Nigel Clement]

Chris,

I'm about to start using this procedure you outlined. Are there any issues with my using your pics and instructions for my staff? I will of course be indicating the source of the information on all the Power Point slides. We are about to start seeding in anticipation of completing construction and having seedlings to put into the system.

[Chris Smith]

I have no problems with my pictures being used for educational purposes. I freely post pics so others can learn by example. I do not consent for my pics to be used for other peoples profit.

[Joe Bifano]

Hey Chris

Are you hand seeding the net pots or using a seeder of some sort?

 

Also Living in Colorado I can get lava rock but it is 300 miles away in a query but I am not sure if it is worth it to drive that far. We can get a 1/4" to 1/2" Scoria at a garden supply in Denver and was wondering if this would work if I screened out the smaller pieces and used the larger pieces for my Bio-filters. What sizes are the cinders? Because you work with the cinders all the time I was wondering if I could crush or change the size of my 1/2" sizes pieces to a manageable size or not.

 

If this can't be crushed or changed then I was wondering about this. We can purchase smaller pieces of lava rock through a site that sells it for Bonsai plants and this looks really small. In your opinion how many quarts of smaller lava rocks can fill the 2x2 foam 62 cells? I do not have a 2" net pot here to be able to figure that out becasue I am just now ordering these and starting my new system soon. If we can get an idea on this then I can see if it would be worth it to purchase just the smaller cinders from the Bonsai company for planting and the larger stuff for my bio-filters.

 

[Michael Warner]

Joe Bifano said:

Hey Chris

Are you hand seeding the net pots or using a seeder of some sort?

 

Also Living in Colorado I can get lava rock but it is 300 miles away in a query but I am not sure if it is worth it to drive that far. We can get a 1/4" to 1/2" Scoria at a garden supply in Denver and was wondering if this would work if I screened out the smaller pieces and used the larger pieces for my Bio-filters. What sizes are the cinders? Because you work with the cinders all the time I was wondering if I could crush or change the size of my 1/2" sizes pieces to a manageable size or not.

 

If this can't be crushed or changed then I was wondering about this. We can purchase smaller pieces of lava rock through a site that sells it for Bonsai plants and this looks really small. In your opinion how many quarts of smaller lava rocks can fill the 2x2 foam 62 cells? I do not have a 2" net pot here to be able to figure that out becasue I am just now ordering these and starting my new system soon. If we can get an idea on this then I can see if it would be worth it to purchase just the smaller cinders from the Bonsai company for planting and the larger stuff for my bio-filters.

 

[Chris Smith]

The cinder I use is 5/8-. It comes very dirty with dust, sand, and small rock. I wash the cinder with water and a 1/4 inch screen allowing the fines to separate from the larger cinder. I use the large cinder in media beds. I screen the fines one more time to remove the sand and dust which ends up in my soil mixes. The twice screened small cinder is between 1/16 and 1/4 in size and that is what I prefer for seeding because the smaller cinder wicks water better and seeds don't fall too deep in the media. The large cinder can easily be crushed into smaller pieces. I do not do this since I am cleaning lots of media for systems that I sell and get plenty of small cinder in the process. Other types of small media should have similar wicking properties to cinder but will require some experimentation. I do not have a volume of media needed for one 2x2 seeding raft. I seed 8 rafts each week which uses a little less than 3 five gallon buckets of media. Each net pot uses between 2&3 floz of media(I dumped a full net pot into a 4 oz yogurt container to determine volume).

[Joe Bifano]

Chris are you hand seeding the net pots or do you use a vacuum?

[Chris Smith]

I hand seed using conventional seed. Vacuum seeders do not work well with conventional lettuce seed because of their odd shape. They do work well with pelleted seed though. I don't use pelleted seed anymore because I am growing my own seed and pelleted seed has a very short shelf life. If I was growing one type of lettuce I would probably go back to pelleted since i would be able to use up the seed before it expires. Pelleted comes in such large quantities it is hard to use up in a small operation before going bad when using multiple varieties.

Each lettuce plant I let go to seed saves me $5-$10 depending on variety.

[Joe Bifano]

Chris I wanted to ask you a question that I think was asked before in this thread but I can't find the answer. I see the photos where you fill the rafts with seeds and then you said that you cover them for 3 days with plastic. I also see some rafts on the floor under the table you fill the rafts on, covered with plastic.

Are you just watering the trays lightly, or are you misting the trays with an atomizer just to start them with water? Is there a small amount of water kept in a shallow tray that we can't see so it wicks up? Could you expand a little more on this.

My system is just getting going and I am getting things to grow really good(finally). I did a few lettuce tests for a buyer and he loved them and wants me to go into production to show him that I can do it the same in the production mode giving him the same quality and the same consistency.

I think my weakest link is my seed starting, germination, to nursery set up. It is taking to long and I need to improve this.

I have tried a peat mixture with perlite and it is okay but we have a source now for scoria in the 1/8" to 1/4" that is real close by so I want to try it.

I purchased a case of 32 round cell trays and have used the 2" net pots in them. I think the peatmoss is too wet and I am not getting the germination rate I should.

Here is what I am thinking that I should do..

1. Start with the scoria rock in the 2" net pots in the 32 cell trays moistening them under plastic in the Utility room for 3 days.

2. Take the 32 cell trays from the Utility room to my vertical shelf's that are constant flow at 1/4" in water depth. These shelf's are 4 high and have about 16" above them so they do not get full sun except the top shelf. Then hopefully the 1/4" nutrient depth will work and wick up what the seedlings need and that depth will not drown them. They grow for 2 weeks in this.

3. Take the 32 cell trays to a nursery table where the water depth would be 4" to 8" and let them grow for 2 weeks. I would build in a shelf or structure that would allow the trays to be at the correct level and have that 4" to 8" of water depth.

4. Transplant to the main rafts and grow out hopefully in 2 weeks and harvest.

The 32 hole trays have a small hole about the same size as the round plastic bottom piece in the 2" net pots that probably is a problem and blocks the hole. I was thinking about melting the 32 cell trays small holes to be larger so I would get more available water and allow more roots to pass through to the deeper nursery troughs. I know that this will be some work to enlarge the holes in the trays. But because I have them I thought I would use them rather than get a lot more foam and the cost of that foam for the smaller rafts plus all the drilling to make them.

Your thoughts would be great.