The Best Plant Growing System?

[GaryD]

Hi Kellen,

A good post.

My system is "best" for ME, because it satisfies my requirements, and helps me reach my goals.......

It really all boils down to an individual's goals and expectations, and what "best" suits THEM.

I agree totally.

One of the wonderful thing about aquaponics is that you can focus on plants......or fish.....or anything in between.

The appropriate technology slant of backyard aquaculture in recent years has even provided us with the wherewithal to grow fish without plants and plants without fish.

For me, it's all about clean, fresh food......and I tend not to get hung up on questions of means and ends.

Gary

[arachdog]

With that in mind Gary maybe you should clarify what your intention was when you started the thread. Do you want it to be a thread to be a random collection of posts where everyone comes in and states whats best for them. Or did you actually have a particular goal in mind like perhaps the most economical, reliable or envionmentally responsible system?

[GaryD]

Hi Arachdog,

With that in mind Gary maybe you should clarify what your intention was when you started the thread. Do you want it to be a thread to be a random collection of posts where everyone comes in and states whats best for them. Or did you actually have a particular goal in mind like perhaps the most economical, reliable or envionmentally responsible system?

My purpose was to stimulate discussion........and to encourage the exchange of ideas and opinions.

And, wherever possible, to stick a boot up the backside of any sacred cows that might be lurking around.

Gary

[Laurie]

There really is no best growing system, what works for you, is the best. I have just put up my new website & it will show you different types, hydroponics, aquaponics, flood & drain, aeroponics etc.
With 66 years of experience between my partner & I, one is always learning.
Check out our website & let us know what you think.

Laurie.


http://www.geelonghydroponicgardening.com

[GaryD]

Hi Laurie,

There's clearly been a heap of work invested in your new site. It's easy to navigate and read.

Good luck with it.

Gary

[mornings]

I would challenge the notion that UVI is an efficient model of aquaponics. They failed to utilize the one strong reason to grow tilapia. Feed is produced by sunlight in the water in the form of algae. This would bring there feed costs way down. At least 1/2 maybe even 1/4th.

And before you say, but there Doctors. That doesn't impress me, I correct doctors mistakes on a daily basis... I'm a nurse

Ravnis,

I don't know a great deal about the production of algae but to make the equivalent food would take at least 7395 lbs. of dry weight algae, which would be somewhere close to 19 tons wet. And, that assumes a protein content of 32%. If it were less it might take a great deal more. Also if the protein content were lower it would take more fish to produce the same plants (a larger system, more pumping, etc).

And, of course, there is a down side to algae. It clogs, it takes nitrogen away from plants and reduces oxygen levels, which can all result in toxicity. Seems to me, making algae economical would be a real balancing act -- but I really don't know. Maybe you can enlighten us.

I would be interested in seeing your methods (What does it add to the size of the system?) to produce algae and your figures as to exactly how much it would cost to produce the algae and what savings, on balance, would really be there after producing it and suffering with it.

I don't Know Dr. Rakocy personally but he seems to have little bluster or self adulation and, on the contrary, has done a great deal to advance Aquaponics, especially in the tropics and the third world. What mistakes exactly to you think he has made and how would you correct them?

m

[Ravnis]

Algae is an interesting plant. It can get its nutrients from the atmosphere and assimilate carbon dioxide as well nitrogen from the air. The one thing it cant get from the atmosphere is phosphorus and potassium and other trace elements. I basically grew my tilapia for little food(compared to the fish in the bigger tank) input simply because they were eating the algae. I did not have room for a second tank in my shed. I added a clear IBC to the system in the sunlight, even though it is widely argued about here. The water approached 95F and I was concerned that my fish would die. The algae went wild and I could no longer see my fish. The plants flourished as well and my tomatoe plants grew to 6 ft in less than 30 days. The fish quit eating the fish food I threw in except maybe a 1/4 of a cup of fish pellet for 20 fish of approximately 1/2 pound in size. I held my breath for a month and netted them out and they were double the size of my fish I had in the tank in the shed. THese had started out the same size. THey had a much larger growth rate, ate practically no food, and I still had fanstastic plant growth (even if the grasshoppers and caterpillars ate most of it).
The water from the IBC tank ran into the growbeds. Our favorite friends, worms, kept the growbed from clogging up, though I can't say for sure whether they ate the algae or not. The algae was trapped in the two feeder beds as those beds dumped into the sump and the water remained clear in the sump and the main tank in the shed.

I would not say Dr. Rakocy had made mistakes, but rather there are discoveries that will make this production system more efficient. It is extremely energy instensive and that has been the main arguments that I have read against aquaponics being a competitive production system. My little quip about doctors was to point out in a light hearted manner that a lot of people assume just because someone is a doctor they are perfect and know everything. I meant nothing personally against Dr. Rakocy.

Unfortunately, I only have qualitative measurements and will have to work more dilligently in getting quatitative measurements. I wish I could say combining greenwater system with aquaponics was a planned and well thought out system design. I just happened to observe this accident.

[mornings]

Thanks Ravnis. I guess I thought you were going through a drying process, which makes it easy to handle and store but its a lot of work.

I'm no longer interested in fish, but I can still appreciate one who has enthusiasm for trying something new. I also realize that doing this sort of thing on your own when you are not funded with much more than the love of doing something, is not easy and typically takes a long time. Good luck. Is there a thread on what you are doing with algae?

Your plants grew when the water was 95F?

BTW, I don't think worms eat fresh algae, don't think they can/will, however, there is a lot of algae that dies in the dark in a gravel bed and the worms, with the help of bacteria, do clean it up. So, worms can convert a this cheap food source into nutrient too.

Hmmm . . . I'll have to think about that, maybe check with Dr. Clive Edwards or some of the worm people. Maybe I could use the algae to feed the worms. Boy would I love that! I read were algae can contain as much as 50-60% protein -- but it sounds like there is quite a variation. You know? I guess you could see it in the output of the plants. The first problem I had with worms was getting the protein % and nitrate output up. But my solution, while being well controlled, is an expensive one.

m

[Ravnis]

The tomatoes and peppers grew, lettuce growth stopped during the 95 F water temperature. I had ordered shade cloth but it took two months to get it in. If it had come in I would have put it on and probably would have not had this event happen. I will try to recreate it again this summer. But plants grow so fast that I have been able to enjoy multiple crops with a 9 month growing season.

A suggestion for you to try. Take a tub of fresh water with a way of stirring the water , an air stone perhaps, add some greensand(iron and potassium) and supertriplephosphate (calcium, phosphate, some nitrate). Let it get good and green and then pour some of this water into a vermiponics bed. I suspect that you will be surprised with the results. I may even experiment with this myself as I believe you are onto something if fish production is not a personal goal. I doubt my aquaponics system would have been as successful if I had not added worms to the growbeds.



Algae like other organisms will expand to there limit and then start dying off. The tilapia feeding on them helped to provide balance. I believe if you constantly add fresh water to the tank to replace the algae/water you remove that you will be able to keep the algae growing.

[mornings]

Thanks Ravnis. I'll give that a whirl -- or something like it. Growing algae is pretty easy to grow at 37 deg lat. If I leave the cover off the tank, algae starts forming almost immediately. I would have to kill it with heat, drying or darkness. It must somehow ferment -- I think, but I'll report back what it takes. Thing is, if your worms are eating it, they are also feeding your plants with cheap food.

Oh, btw, in fairness to Rakocy and UVI, they may be feeding purchased food because it is a easy way to control nutrient input and the feed is still a very small % input cost. Depreciation of plant is usually the most significant cost. May be a trade off.

m