Sunday, December 20, 2015

Hydroponic Automation System Completed

Yesterday (Dec 20th 2015) I completed the full automation system (Rev 1.0) which now manages one of the two grow NFT beds.  It runs fully on Wattmon, my automation platform and monitors the following parameters:

  • Water Temperature
  • Ambient Temperature
  • TDS (Total Dissolved Solids)
  • pH
  • Water level (high/low)

It also has three dosing pumps:
Acid Pump
Injects Phosphoric acid to regulate the pH down (our water has a very high calcium content and tends to move to about 8.5 pH).  pH is regulated around 5.5-6
Nutrient A + B pumps
Whenever the TDS drops below 900 ppm (about 1.5 EC) it will inject a bit of concentrated nutrient solution from the stock tanks.

Water Solenoid
Whenever the water goes below the low probe it will switch on the solenoid and replenish the tank until the high probe mark.

The next (and final) thing I want to add is a flow meter to monitor the actual water consumption of the system at different times of the year.

5 liter cans of A and B solution with dosing pump.  Acid is in the can to the left.

Tuesday, November 24, 2015

Friday, November 6, 2015

 Microgreens! Second round. This are 4 days old!! They are growing so fast!

Trying to grow microgreens on their final containers. Starting with no light and a close container. This are 2 days old. 
Normal mustar, yellow mustard, alfalfa, & metti
 Sprouting rucola on a normal cleaning sponge...lets see how it works!

The system after the rain...we have to re-adjust the silpaulin 

But the plants still looking good!

Thursday, October 22, 2015

Starting to prepare microgreens!!
We first soak them for a day in water inside and only then we sprinkle them on top of the coco dust

Top Roof -  Starting with kratky method. We will prepare one more system this week!

Just transplanted...

 The hydroponic systems....growing...
Soon we will have to transplant the flowers to leave place for something edible!

At the base, the green trays with the latest seeds sprouted

Buckets shared by melons (melon de piel de sapo.....MMmmmm so good!)
and tomatoes with the kratky method.
The tomatoes are doing well and the melons had been heavily attack by this worm 
that i show on the pict down here...
Does anybody knows how to solve this problem? 
We try to spay the plants with soapy water...but no luck...

 Here the fatty guilty worm...what is your name, eh???

Sunday, October 18, 2015

Harvesting and getting ready to sell

We are harvesting 200gr mix of mix lettuces and 2 varieties of arugula. Soon we will start with microgreens too!


Monday, October 12, 2015

NFT System Running

It is time to update you on the progress so far.  We realised in March that the Kratky system was great between October and February but as the temperature in the tropics edged above 35 degrees C the water temperature heated up and plans started to rot and wilt.

This summer we visited Nathon Farms, a hydro farm in Koh Samui, Thailand and met Mrs. Lex who showed us her system and gave us invaluable information on growing hydro in the tropics.  We have replicated her system which uses the NFT method and have been growing lettuce and arugula since July.  Lettuce does not like the very hot days but arugula did great even on 40 degree days.

She also shared her nutrient formula which we are using to grow the plants.  It is easy to make and uses a combination of standard elements, most of which are readily available in India.

Here are some pictures of the setup:
The first system has been running since July, the second one was just complete on the 10th of October.

Lettuce and arugula

Young lettuce growing in the PVC pipes

A bucket system experiment to grow tomatoes and melons

Second system getting ready 

The first seedlings going in!

But Is It organic?

I have shared this article by Roger H. Thayer because I think it is very well said and may help clear up some questions about organic vs. inorganic growing.

I'd like to have a dollar for each time I've been asked, "Is it organic?", since I started in the hydroponics business in 1972, I'd be rich! Is hydroponics organic? Is it chemical? What are the similarities and the differences? These questions have never really been answered to the satisfaction of most people as evidenced by the fact that I am asked the same questions today as often as I was nearly 20 years ago. Many people are confused by the word "organic" as it means different things to different people.

To the farmer, the word organic means no pesticides or herbicides. No potentially toxic or hazardous materials are to be used on crops to control bugs, weeds and diseases. To the gardener, the word usually means all of these things, plus that no unnatural or manmade chemicals are to be used. Only "organic" fertilizers and natural controls. They must: be made by nature, not by man.

To the chemist, on the other hand, the word "organic" means something totally different. In chemistry there are two distinct branches: inorganic and organic chemistry. Inorganic chemistry deals with non-living materials.

Organic chemistry focuses on the carbon and carbon containing compounds, typically associated with life. Biologists and botanists, and others who deal with the life sciences, are stuck in the middle. When they deal with chemists and other scientists, they have to adhere to the chemical definition of organic. When they talk to the farmer or gardener, they have to talk in different terms. To them, organic means "natural," not carbon based. They can say one thing, but really mean something else.

There is really no difference between an atom, mineral or the element itself. What matters is whether or not they are in a form that is non-harmful and that can used by plants. If so, they are beneficial whether natural or manmade. Plants do not take up carbon at the roots, they get all they need from the CO2 in the air, so the term "organic gardening" is confusing. The same minerals are needed in either hydroponic or organic growing. These minerals are provided to plants in the organic garden as they are released from organic matter by the action of microbes, worms and bacteria. In hydroponics, these same elements are provided by water soluble mineral salts.

In hydroponics, mineral elements are provided by the use of mineral salts. These may be either naturally derived of manmade, but most have been purified and processed so that they are water soluble and in a form that can be used by plants. Many start out as mined minerals or naturally concentrated deposits that are dissolved and processed into compounds with a definite molecular structure and composition. In the refining process, these mineral salts are usually purified to remove heavy metal contaminants and toxic substances that could harm plants or people. Since the chemical composition is precisely known, different mineral salts can be combined to form a balanced hydroponic nutrient. When dissolved in the proper proportions with a good quality water, a hydroponic nutrient solution can provide all of the mineral elements needed for plant growth without soil. By its nature, the hydroponic methods eliminates much of the uncertainty and guesswork found in organic growing. Some adjustments are normally made for proper pH, controlling nutrient concentrations (parts per million) and to maintain balance between the nutrients provided. These are usually easy adjustments and within the control of the grower. In a well-built hydroponic installation, all conditions are controllable so optimum plant growth can be achieved, even surpassing nature.

But is it organic? Can a hydroponic plant nutrient be classified as organic? Probably not, unless you go back to the chemical definition of the word, that is a substance that contains carbon. By this definition, many "chemical" nutrient formulas would be considered organic. These include the chelated trace elements as well as urea, which contains carbon in the form (NH2)CO2. It is also possible to define a hydroponic nutrient solution as organic by drawing on the definition many people use that organic is "natural".

Most of the mineral elements used in hydroponics start out as mined rock or mineral deposits which are as natural as the earth itself. The important point is that it is not the elements that are different in organic and hydroponic growing, it is how these elements are obtained and delivered to the plant.

Pros and cons. There are definite advantages and disadvantages to both organic and hydroponic growing. land is still available for conventional agriculture. With proper techniques and care, organic growing can yield good, nutritious crops on a large scale with minimal expense, although it can be labor intensive. Organic growing has an element of uncertainty, as already mentioned, but with care and knowledge, that can be kept to a minimum. Still, optimal mineral and element composition is going to involve guesswork unless expensive chemical soil analysis is routinely done and soil amendments are used to correct deficiencies. Most of the amendments used in modern agriculture happen to be the exact same mineral salts that are used in most hydroponic nutrient formulas. The advantages of hydroponic growing are increased yield through complete nutritional and environmental control, the absence of competing weeds and soil-borne diseases, increased crop density and reduced water consumption. With recycling systems, hydroponics uses one-tenth the amount of water used by irrigated agriculture. Growing media are easily sterilized and conditions can be altered quickly to suit specific crops or the growth stage of a particular crop, such as during flowering or fruit production.

The main disadvantage is the initial set-up cost. The cost of a good installation is fairly high, but if quality materials are used that cost can be spread out over many years. What about using hydroponic nutrients in an organic or soil garden! There are many advantages to this kind of hybrid application, combining organic compost with hydroponic nutrients similar to Mittleider Gardening. Care must be taken not to overdose the plants with such a system. If a full-strength chicken manure is used with a full-strength hydroponic solution the plants can be burned. Handled properly the system could eliminate mineral deficiencies. Plants grow faster and healthier as long as pH, drainage and water/nutrient retention are adequate. Because the plants are healthier they are able to ward off insects and diseases, further enhancing yield.

Monday, March 30, 2015

Designing a hydroponic automation controller with Wattmon part 1

I have been playing with hydroponic systems since several months and have found that it requires regular checking to ensure that it does not run dry and that nutrients and pH are within acceptable limits.  I have been planning to use a Wattmon to do this but only just got started.  The idea is to first monitor the system and send email alerts when user intervention is required, and at a later stage add automation to keep everything healthy.
There are many parameters that affect a hydroponic system, but the most important ones are pH, EC and water temperature.  The pH needs to be in an optimal range (usually between 5.8 and 6.5) in order to ensure proper nutrient uptake by plant roots.  The electrical conductivity (directly proportional to TDS or total dissolved solids) indicates the strength of the solution in the water.  This will vary as plants absorb nutrients or water is added.  An EC of 1.5 to 2 uS is quite commonly used.  This translated to between 750 and 1000 ppm of dissolved solids.  Finally, water temperature affects the growth of plants.  Cool weather plants suffer when the water temperature is high.  The available oxygen decreases as water temperature increases too.
The WattmonPRO has several IO lines which will be used for this project.  Two analog inputs will be used to measure pH and TDS respectively.  The onewire port will be connected to a waterproof onewire sensor.  Two digital inputs will be connected to float sensors in the nutrient tank to monitor water levels. An auto/manual switch could be connected to enable a manual servicing.
Eventually, 4 digital outputs will be connected in the following manner: 1 will open a solenoid to fill the tank with water. Three outputs will connect to small dosing pumps for stock solution A and B, and acid to regulate the pH. The 5th output could be used to control a pump or other solenoid if required.
PH is sensed using a pH probe and an interface module that generates a 0-5v signal. This is then calibrated in the Wattmon and the pH is displayed on the dashboard.
The TDS module generates a sine wave and passes a small current through probes in the water.  The amount of current that flows directly correlates to the amount of salts.  This is amplified to a 0-3.3v output and read by the Wattmon.
These values are currently being logged, and the next step is to add some automation based on the values, in a small test tank in my office before taking it to the live setup.

Sunday, March 22, 2015

SeaPonics experiment part 1

So what is seaponics and why am I interested in it?

Seaponics is a method of growing plants and vegetables on diluted sea water along with some macro nutrients to provide the nitrogen, potassium and phosphorus.  The idea is that sea water contains most of the element in the periodic table, and thus will supply the essential micronutrients the plants need for a balanced and healthy growth.  It sounds far fetched at first but if you take a second to think about it, it makes sense.  A researcher Maynard Murray already experimented with this extensively and wrote a book about sea agriculture.  So this has been around for over 50 years and the question is why has it not been adopted into mainstream agriculture, especially in coastal areas?
I don’t have an answer to that but since I live pretty close to the sea and have access to what he describes as ‘sea solids’, which are created by allowing sea water to evaporate in a landlocked area and scraping the remaining solids off, I thought it was certainly worth it to give it a try.
There are various formulas for this, but I used one I found off the net and adapted it to the various fertilizers I had on hand.  Looking at the formula closely and the types of nutrients it provided via sulphates, I actually concluded that it provides everything that standard hydroponics takes care of apart from Molybdenum.  So theoretically the plants should grow just fine on this mix without the seawater.  However, adding the seawater may make them flourish – it remains to be seen.  I have started an experiment with two melons in 75l barrels.  One contains the seaponics mix, and one contains the standard hydro mix we have been using.  Both will be grown using the Kratky method, without aeration.  Here is a picture of the setup on day 1.

Standard hydroponic formula day 1

Seaponics formula day 1

I will update this blog to update you on the progress.

I also planted a Kratky type bed of lettuce with the same mixture as shown below:

Kratky bed of lettuce day 1 (shaded part) using seaponics formula

Thursday, March 19, 2015

Kratky hydroponic setup in a small greenhouse

Here is a setup we helped with the other day.  A friend built a special greenhouse to test out the Kratky method of hydroponic farming.  We brought some seedlings and nutrients to add to the water. Let's see how it goes!  It is already mid March and getting hot so it may be challenging.  He put sand around the beds which he plans to keep moist in summer, this may help keep the greenhouse cooler.

Tuesday, March 17, 2015

Dissolved Oxygen in a Kratky System

After running the Kratky hydroponic systems for three months, from December through March, it became clear that this would not work without through summer in the tropics.  As the temperatures started to rise above 32 degrees C, the lettuce started to wilt during the day, a sure sign that something was wrong.  The water level was still high in the beds, so that wasn’t the problem.  However, the water was not looking good – it was coated with a slime and the roots all looked rotten.
After doing some more research I decided to try adding some oxygen to the water.  First, I washed all the lettuce plant roots.  Many were rotten and just washed right off.  I then placed airstones in each bed and ran a line to a central air pump for aquariums.  Within two days the lettuce started looking better and I could see the tips of the roots were now white, although the temperature had not changed drastically.  The plants that had started to bolt remained at the same height and started forming new leaves at the top.
This taught me a very important lesson:  The dissolved oxygen level in water is extremely important, and it is highly dependent on temperature.

Here are some interesting insights:

  1. The higher the temperature of the water, the more it expands leaving less place for O2 molecules.  
  2. Water and air exchange O2 molecules through the water surface, and this is the reason air pumps help since they agitate the water constantly, creating a space for this exchange to take place
  3. A slimy surface on your water will guarantee that very little or no O2 will enter your water
So for those of you attempting Kratky in hot climates and seeing problems, try adding oxygen and see whether that helps.

Sunday, March 1, 2015

Introduction to Rooftop Hydroponics

Welcome to our blog on rooftop hydroponics!  Monica and I (akash) are based in Auroville, South India and have been playing around with various types of rooftop gardening systems over the last few years. In 2012 we built an aquaponic setup together with a friend, and spent a year gathering data and fixing problems.  Our experiments ended with a massive cyclone that destroyed the greenhouse.

My experience with aquaponics

Aquaponics is a great system when it works right.  Our initial prototypes worked pretty well but when we moved to a larger system, with 6000l of water and about 10000 liters of gravel media, things became difficult to maintain.  You can see some pictures of the setup on our blog,
After the system was destroyed we lost all interest in farming for a while, since the results were not what we expected and the work was much more than anticipated.  Again, I would not wish this to influence anyone’s enthusiasm and I have been following Murray Hallam and his adventures and successes – it just did not work well for me.

Rekindled interest

In late 2014 I started researching hydroponics and came across b.a kratky and his experiments.  For those of you who are not familiar with him, he is a professor at the university of Hawaii and he came up with a non-circulating system with suspended net pots that make it very easy to grow greens such as lettuce.  He is not the first to have done this, in fact a team in Taiwan had been testing this already, but somehow he is the one that popularised it and hence it is now known as the Kratky method.

The kratky method

The great thing about this type of setup is that it is literally zero maintenance.  We have spent the last two months experimenting and perfecting a way to minimise the amount of effort required for each step of the process from seed germination to transplanting.  In the following posts I will focus on each of these and how we do it.