GrowInBox

The measurments were taken with this spectrometer.

Wavelength Accuracy is 2.0 nm

This is the capture from the logger pro program provided to my school from veiner.

This is what was promised to me (link):

And this is what another customer sent the seller (source);

The CSV for the measurements is in the files section of this project.

The last project log was on the 3rd of november, 2015.

So what happened?

Some strawberries grew.

They didn't taste that great.

Now the strawberry is gone.

Getting back to this project in July.

7th of november 2015 (day 53)

11th of november 2015 (day 57)

21th of november 2015 (day 67):

I tasted the strawberry.

Surprise, it was bitter as fuck.

Hi!

I have a lot of school work to do this week, but I decided that some thing just need to happen today or as soon as possible. So I bought a new fertilizer.

The old one - plant food - TNT Complex from hesi has a NPK of 323 which is ok for the vegetative stage of the growth, but probably not so great when a plant is flowering. And because I want big, red, sweet strawberries, I looked into the fertilizers for strawberries.

This one looked solid. The NPK is 24-12-32, if we divide the values with 4, we get the ratio, which is 6:3:8. The closes thing I could find to that was Organic Iguana juice bloom from Advanced nutrients, which has the NPK 4-3-6. If I would combine it with the hesi which has NPK 3-2-3, I would get something like 7-5-9, I guess. I'm not sure if I can do calculations like that. Probably not ... Anyway, this is how I'm going to experiment.

The NPK value is given per volume of the fertilizer. If I give only half the volume of a 3-2-3 fertilizer, I should get 1.5-1-1.5 at the same value (if I would dilute if with water) - I guess.

Till now, I have given my strawberry only 2.5mL/L of the hesi TNT fertilizer, but I think I could have gone upwards 5mL/L.

The TNT fertilizer is also worse for the strawberry, because this fertilizer is for soil only and I'm using it in hydroponics ... And the seller also said that it would be better to use organic fertilizers if I'm planing to eat the strawberries but I don't really care about that.

On the Advanced nutrients fertilizer it says to use 4ml/L of fertilizer.

So I'll have a NPK of 4-3-6 . And if I add only half the volume of the hesi TNT - 2ml/L, I'll get half the NPK (RIGHT?!?!) so that gives me 1.5-1-1.5 and if I add this up, I get and overall NPK of 5.5-4-7.5 which is kind of the 6:3:8. ratio Kind of. There is a little too much potassium but whatever right. I hope I don't fuck this up.

So, because I only need 1L of the solution, I used 4ml of AD bloom and 2ml of Hesi TNT. I also added some super vit because I guess it can't do any harm and lowered the pH of the solution to around 6. I also added 2mL of root stimulator.

The EC meter showed 800 PPM which is in the right range (800-900) according to this site.

I also took apart the pH meter. First I just thought about buying the 3xAG13 batteries and using the pH mater as it is, but then I saw the price in a shop ... Around 7€. Kidding me? No way I'm paying more for the batteries than I payed for the meter :D. So I'm probably going to power the meter from a 4.5V constant voltage source. When I took it apart I saw a big IC and decided to google around to see what people have done with it, if anything.

Then I came across this awesome blog!

http://overskill.alexshu.com/cheap-ph-meter-hack-for-arduino/

This guy decoded the signals going to the LCD into the pH value.

His solution is nice but .. I don't know. Using shift registers doesn't sound fun and practical to me. I think that the pH meter has an op amp in an external IC.

There is the Texas Instruments logo and the footprints seems to be the one of an op amp. I also think that a pH meter needs to include an op amp to work.

On the IC it's written 385B12 42M AD0564, but I can't find a datasheet. I don't currently have the time to look into this, but I eventually will I guess. It would be ideal to get the analog signal into a high resolution ADC, which would send the value via i2c to the master microcontroller. That'd be really simple and elegant.

There was also this idea on the arduino forum, which is similar to mine.

I also finaly received the LED drivers! Fuck yeah. There is also a nice clip for the DC side, I really like that. It has polarity protection which is really nice.

I decided to also buy salad seeds, so I would grow salad and beans in parallel under different lights. But I will start working on that over the weekend or maybe even later. School stuff to do ... To bad right?

“Doubt kills more dreams than failure ever will.”
Suzy Kassem

It's day 44 for the strawberry. A second flower is emerging.

I've taken a new jar, cleaned it and wrapped around it 3 layers of aluminium foil and changed the air stone.

I think it's pretty dark in there. Only time will show.

I also scraped some of the algae from the net cup and the rock wool cube. The roots are growing nicely (at least for now).

The nutrient solution is the same as always, 50% strength of the root stimulator and 50% strength of the plant food. I lowered the pH with Sodium bisulfate, which is from the pH minus chemical for use with pool maintenance.

A fan was also added to help to strengthen the stems, as it was recommended in the comments (thanks).

I also took apart the ultrasonic mist maker. I was heavily disappointed when I found out it was just a block of plastic in which all the electronics were.

The spring came out of the inner block of plastic and made a connection to the piezo crystal. There was also a metal ring around the piezo and some rubber so water couldn't get to the spring I guess.

The red arrow is pointing on a big, at least 2W ressistor, and the blue arrow is pointing on a weird metal element. I didn't hack it apart further because it seemed meaningless.

I also read about pollinating the strawberries.

"Use a tiny paintbrush to transfer pollen from the flower's male stamens to the female pistils. The numerous tiny pistils are grouped on a stem in the center of the blossom. The stamens are the parts of the flower covered in pollen. Act soon after a flower blossom opens for best results."
(source)

(Image source)

I've done that today (though I didn't find a brush so I used a cotton swab) and 2 petals fell off ... Strange. Maybe the strawberry has pollinated herself already.

It's been 43 days since I've pushed the runner in the rockwool cube and 21 days since the strawberry was in my hydroponic system. The system itself went through some changes as you can see below. Firstly I used an ultrasonic humidifier to make the mist, but it heated the water so I switched to a deep water culture system. Also note, that ultrasonic humidifiers may not be okay for aeroponics, because the droplets may be too small! More about this below.

The main two ideas were:

I wanted to use an ultrasonic humidifier for making the mist, which was wrong!
Not only does the mister heat the water to 36°C (96.8°F), the droplets may also be too small.

NASA research has shown that plants are more willing to absorb nutrient water in 5 to 50 microns droplets more effectively than any other sizes. Water droplet size is crucial for sustaining aeroponic growth. Too large of a water droplet means less oxygen is available to the root system. Too fine of a water droplet, such as those generated by the ultra-sonic mister, produce excessive root hair without developing a lateral root system for sustained growth in an aeroponic system. (Source)

I've checked here that the ultrasonic mist water droplet is about 1 micron in size.
But then, there are people who claim that it works fine.

I will write about aeroponics and my ideas for it in a future log, for now, I'll just document what I've done so far and how it worked out.

I decided upon only 2 compartment system without the water pump because it was simpler. I used polymorph because it was at hand and it's cool because you can melt it with boiling water and reuse it as much as you want.

After sealing the plastic to the container I still had some water leaking, but I didn't really care. I just wanted to finish everything that evening (7th of October).

The fan pushes air into the system.

The aluminium plate with LEDs fits tightly between the shelf holders and I've also tied it with wire wrapping wire - the best investment of my life.

Although I would recommend you get slightly thicker wire, because I can still tear this wire apart fairly easily with my hands and that's why I have to use more wires in parallel.

I'm using 5x10W cold white LED chips in parallel, connected to 12V from the ATX power supply. I chose cold white LEDs because they produce more plant-usable light.

(Source)

The water solution consisted of 50% strength TNT complex (Hesi) and 50% strength root stimulator (Biobizz). I also added some SuperVit (Hesi) which contains vitamins and minerals. For pH down I used ascorbic acid, (vitamin C).

I bought 100g in powder form for like a euro or something, although I'm not sure it's the best chemical for pH down, since the pH came up almost every day.

I ran the humidifier quite irregularly. Some days I'd turn it off over night and some days I'd let it run all the time. I also thought about and UPS for the ultrasonic mister and a timer, but I never got to actually automating anything. I was really lazy about that. I had an idea thought.

This is the root grow from day 25 do 32.

And this is the top growth from day 24 to 43. Some days I took two pictures.

This is a photo from the 33rd day. Those little roots fell off when I pulled on them. And I pulled really softly! They must have rot or something. Maybe the mist was at 36°C and therefore too hot for the roots.

Healthy strawberry roots (source):

On the 7th of October (day 22) the roots looked normal and strong.

When looking at those photos I realize what was meant in the quote on top of this log:

Too fine of a water droplet, such as those generated by the ultra-sonic mister, produce excessive root hair without developing a lateral root system for sustained growth in an aeroponic system. (Source)

On day 33 I threw together a deep water culture system in a mason jar because the aeroponic one was smelling like ammonia and I deeply care for my strawberry and I thought it was better to think this through than to kill her. Also the first system was leaking from the bottom :D. The solution was the same as the last time.

But because the mason jar is clear and well oxygenated ...

BOOM. Algae. This was only 2 days (day 35) later.

5 days later (day 40) ...

Today, day 43. The rock wool cube transformed into algae wool mush .. Ugh ..

In the past days PPM kept falling and the pH was coming back up to 7 every day, even though I would add vitamin C to lower it. The light was usually running for about 16 to 17 hours a day. I've read that 14h is ideal for strawberry, but it seems to grow just fine with more hours.

I really need to change the reservoir and clean everything and add a new solution ... I'll try to do that ASAP. I have also ordered a digital pH meter from aliexpress sincer the readings would be more accurate.

“Live as if you were to die tomorrow. Learn as if you were to live forever.” - Gandhi

Here I will quickly go over two items I received because they seem interesting.

This air pump costed only $1.51 ! It looks used but works as it should. I don't know what type of pump it is so if you have in idea, please comment below.

This is kinda how it works ...
And it works rather well.

I also took apart the digital timer which was crazy cheap ($6.54).
The build quality is amazing, but I have yet to test it out. I'm still waiting for the LED drivers which are taking a long time to arrive :(. My beans are just waiting to be germinated!

If opportunity doesn't knock, build a door.
Milton Berle

The new strawberry lives!

I've marked the 15th of September as day one for the strawberry clone.

This is the mother plant:

Below you can see how the roots changed over time and how a new leaf was formed. Do note that the cube was standing in water without any additional nutrient solution most of the time. It can also be seen that algae has grown on the rock wool cube, to bad I didn't take care of it before because now the problem seems to continue (more about that in a future log).

I'm ending this post with a picture from a movie called The Virgin Suicides (1999).