Passive Hydroponics Thread

[Eric Warwick]

This is a thread for theoretical musings on passive hydroponics that I am combining with a question I have for a couple of systems. I figured any talk about my system plan would spawn a purely theoretical discussion, so I wanted to keep this all on one thread—to make it easier to come back to it. Anyway, past this is my system question, which you can skip if you like.

The above is a crude diagram of the two systems I doodled while in class. The perlite culture is similar to a raised bed with sub-irrigation, except its medium is perlite. The 190L tank feeds the perlite culture with fresh nutrients based on the volume in the tank, using a float valve. Every once in a while (say once a week) I’ll mix fresh nutrients*, and the reservoir will be refilled. The plants planned to be grown range from root crops (radish) to eggplant, to tomatoes, to greens. I’m either going to build it with a shallow strip of H₂O at the bottom, and a capillary mat to separate the two, or more cheaply, with just perlite. The dimensions of the bed are undetermined, but will be dependent on the outflow.

The second system is more self-contained, but needs automation. It stems from a successful experimental design from last year, 2/3 media and 1/3 H₂O. (I was also thinking of DWC.) Since I plan on growing ~20 tomatoes and however many peppers and… I need to get a self-watering system. I was thinking of connecting them with PVC to common reservoir of about 100L, all at equal height. What do ya’ll think of this? Any suggestions? Oh, and don’t worry, I’ll make an aquaponic system eventually, just not this summer. 

*"Organic" nutrients from Fox Farm

[Eric Warwick]

Here are some links that are useful on the subject: http://www.diy-hydroponics.com/passive-hydroponics-systems.html http://www.ctahr.hawaii.edu/hawaii/downloads/Three_Non-circulating_... (Vlad's link)

[Vlad Jovanovic]

Sounds interesting Eric.

[Eric Warwick]

http://blackberriesareforpicking.blogspot.com/2013/02/passive-hydro... I was bored, so I wrote this.  I describe how to make a few systems--and there's pretty pictures!

[Ted Ansink]

Eric,

I just got into learning about hydroponics and aquaponics this past summer.  I did everything outside during the summer and had good luck with an aeroponics system I made.  I also tried some non-circulating hydroponics on lettuce and it seemed to work great.  I did one with hydroponic nutrients and another with aquaponic water that I took from a friend that has a large aquaponic system going.  They both worked well.  I will be trying a couple of new things this summer, but the non-circulating system seems to be the easiest thing in the world to do.
Eric Warwick said:

Here are some links that are useful on the subject: http://www.diy-hydroponics.com/passive-hydroponics-systems.html http://www.ctahr.hawaii.edu/hawaii/downloads/Three_Non-circulating_... (Vlad's link)

[Eric Warwick]

Yeah, I found passive hydroponics to be the easiest one--especially outside. What kind of system did you design? 
Ted Ansink said:

Eric,

I just got into learning about hydroponics and aquaponics this past summer.  I did everything outside during the summer and had good luck with an aeroponics system I made.  I also tried some non-circulating hydroponics on lettuce and it seemed to work great.  I did one with hydroponic nutrients and another with aquaponic water that I took from a friend that has a large aquaponic system going.  They both worked well.  I will be trying a couple of new things this summer, but the non-circulating system seems to be the easiest thing in the world to do.

[Ted Ansink]

Eric,

I had one big rubbermaid tote for a sump and then pumped the water and nutrients through PVC into four other totes and had nozzles to spray the roots.  Had problems with water running out from under the lids, leaking where the PVC was going through the totes, and plugging of nozzles.  I am going to try to solve the nozzle problem this year by putting a big 50 micron filter on the discharge line from the pump and I have worked on the lids so the leakage has stopped.  The leaking where the PVC goes through the totes will be corrected this year with silicone, since I only break them down at the end of the year to put under the porch.  I tried using plumbers putty last summer.

The non-circulating is amazing to me.  I have taken the pictures that I took of the growth and shown them to some professionals after I have talked to them and they told me it could not be done.  Everyone of them was amazed.

Eric Warwick said:

Yeah, I found passive hydroponics to be the easiest one--especially outside. What kind of system did you design? 
Ted Ansink said:

Eric,

I just got into learning about hydroponics and aquaponics this past summer.  I did everything outside during the summer and had good luck with an aeroponics system I made.  I also tried some non-circulating hydroponics on lettuce and it seemed to work great.  I did one with hydroponic nutrients and another with aquaponic water that I took from a friend that has a large aquaponic system going.  They both worked well.  I will be trying a couple of new things this summer, but the non-circulating system seems to be the easiest thing in the world to do.

[Eric Warwick]

I'd like to see those pictures! How big was your non-circulation system? What was your medium? I used basalt/lava rock for a tomato plant, and it did alright after I watered it correctly, until the roots grew into the resevoir.

[Ted Ansink]

Added a time lapse album to my page to show the growth that I had.  After the initial nutrients were added, nothing more was done to the lettuce with the exception of putting a covering over the top when I thought that it was going to rain.  Lettuce was grown in 2" net pots with a coco fiber and vermiculite mixture.  Plants that were put in had been started in plain water and put in the system when they were about 2 weeks old.

[Bart]

Awesome test Ted, couple questions. What nutrient solution was used for the hydro version? Did you make the solution up yourself?

For the test using aquaponic solution do you have any sense of what the nutrient levels were when you started?

Very cool and interesting what you are doing, I am hoping to build at passive system in the next couple months as well.

Great thread Eric! :D

[Ted Ansink]

Bart,

I used General Hydroponic Flora Series nutrients for this grow out.  I only used the micro and grow.  Since it was lettuce, I did not use any bloom.  I used 7.5 ml per gallon of water.  I have no idea what the nutient levels were since back then I did not even have the instrumentation to measure it.

I also did one where I took water from a friend that had a commercial aquaponics system going and I did it the same way using the fish water instead of the General Hydroponic nutrients.  It seemed to work just as well.  I will try to get pictures of that experiment posted next week.  I am on the road right now.

You can learn a lot more about this passive system by searching for non-circulating hydroponics in google and/or youtube.  The way this was so easy, I am not sure if I will ever do lettuce any other way in the future since it is only for my own use and not for commercial production.  Just get a 6" tall tote, drill holes in the top for the net pots, Make sure that it gets covered outside when it rains so you do not drown the air breathing roots, and 5 - 6 weeks later taste the fruit of your "non-work".   I also understand that it is good for cilantro, pak choy, and spring onions.  I will be trying them soon and see how that works out.  

Ted

[Bart]

Seems the good folks at General Hydropoincs don't want to share their secret formula LOL - big surprise there I guess.

I'm most interested in using the aquaponic's water anyways. My thought is to use this technique as a way of expanding my current grow area anyhow.

I did some utubing as suggested and one guy was saying he had a problem when he mixed slower growing lettuce with some faster growing bok choy in the same system - the bok choy grew so fast it took up the solution at a pace the lettuce root's were not growing fast enough to keep up and the lettuce just struggled. Based on that, sounds to me like small batches of same speices is the way to go.

Looking foward to those pics - thanks for sharing.

 

 

[Ted Ansink]

Bart,

I saw the video on the pak choy next to the lettuce.  I think that if you are growing for food for yourself, you could use 16 quart totes with 4 to 6 net pots in each one and start each one about a week or two apart. Keep each one to one type of plant.   They have a small footprint and would not take much space.  That should keep you in greens the whole summer.

Found another good video.  Don't know if you have seen this one yet.  This guy has a lot of good hydroponic ideas that could also be converted to aquaponics.        http://www.youtube.com/watch?v=r3tz5LVVR_o

Still on the road.  Will try to get the aquaponic water/non-circulating pictures posted early next week.

Ted