Exploration of salt tolerance of plants native to California’s San Joaquin Valley.

Our group is using the WISRD Hydroponics Lab to test the salinity resistance of Basil.

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Trial 1

Note: These are not the desired results, so we will be re-testing until our graph appears to be in accordance with the principle’s of Behr’s Law, meaning that the graph will be linear; absorption increasing as concentration increases.

Concentration (Molarity)                                                Absorption (%)
H2O                                                                                     Control

0.5 M                                                                                    0.127
0.7 M                                                                                    0.106
1.0 M                                                                                    0.060
1.3 M                                                                                    0.077
1.7 M                                                                                    0.072
2.0 M                                                                                    0.073
2.3 M                                                                                    0.049
2.7 M                                                                                    0.127
3.0 M                                                                                    0.60

-Dani B.


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Hydroponics Plan 2018-2019

Longterm Goal: To test the salinity tolerance of plants

Begin Running Lab Monday, November 12

**Must start by above date.

  1. Caps
    1. Reprint – Wednesday, October 31 through Monday, November 5
    2. Test/ Revise – Monday, November 5
      1. **same caps we tested before, minimal testing and no revision expected
  2. Supplies
    1. Send out supplies order – Thursday, October 11
  3. Building Lab
    1. Begin Construction – Monday, November 5
    2. Check/Finalize – Wednesday, November 7
    3. Test Run Lab – Wednesday, November 7 – Thursday, November 8
      1. Split Plants (3) – Thursday, November 8
    4. Run Lab with Plants – Thursday, November 8
      1. **Above is the ideal date, can be pushed back to Monday, November 12 if necessary
  4. Website
    1. Construct Website:  Monday, October 16 – Monday, October 29
      1. Finalized Version – Wednesday, October 31

Plan 2017-2018

Step 1: Finish creating solutions and test molarities under the spectrometer
Finish Date Goal: Sunday, January 14
a. We are still waiting for a new shipment of sodium chloride to make the rest of our solutions. So far, we have done 0.5, 0.7, 1, 1.3 molarities.
Finish Date Goal: Before break (Friday, December 15), if sodium chloride does not arrive Monday, January 8.
b. When we finish making the solutions, we will test each molarity under the spectrometer and create a calibration curve.
Finish Date Goal: Friday, January 12

Step 2: Building the new hydroponics lab
Finish Date Goal: Before spring break
a. Scale down the lab design to 0.5 and create a rendering
Finish Date Goal: Friday, December 15
b. Make a list of what parts we need
Finish Date Goal: Tuesday, January 2
c. Identify what parts we have
Finish Date Goal: Friday, January 5
d. Buy parts and/or deconstruct the old lab to collect materials
Finish Date Goal: Tuesday, January 16
e. Construct the new hydroponics lab
Finish Date Goal: Monday, April 23
The above date will probably be adjusted, we don’t have experince building a lab and will revise our prediction when we begin building.

Step 3: Growing the plants
Finish Date Goal: TBD, At least after Monday, April 30
a. Finalize lab setup: 4 tubes, Tube [a] containing lowest (exact amount to be determined) salinity level, Tube [b] containing medium-low salinity level, Tube [c] containing medium-high salinity level, Tube [d] containing high salinity level, with six plants per tube. Troubleshoot if needed.
Finish Goal Date: Friday, April 27
b. Figure out number of grow days most accurately matching the number of grow days in the San Joaquin Valley.
Finish Date Goal: Monday, April 30
c. Grow plants for number of grow days in San Joaquin Vallley.
Finish Date Goal: TBD

-Dani B.


[expand title=”Open Notes” swaptitle=”Close Notes” swapalt=”Close Notes”]

May 22, 2018

Updated by: Dani B.

Today is our last day of WISRD for the schoolyear. Sadie and Ximena will be in WISRD next year, but I won’t be returning until the 2019-2020 school year. This week we’ve gotten our caps printed, finished our second PVC pipe, cleaned up the lab, taken inventory, and written our reflections. Next year, we plan to put together the different components of our lab and start growing.

-Dani B.

May 21, 2018

Updated by: Dani B.

Our caps finished printing today! Sadie and Ximena are upstairs sanding and sealing the caps to the PVC pipe, which we drilled and sanded last week. I went down to the lab to take inventory of everything we have, and to clean up and organize the lab for next year. Here’s the list:

Plant Bloom Nutrient (2)

Plant Growth Nutrient (2)

Utility Pail (6)

Pump (2) (One is broken)

Reservoir Tank (1)

Reservoir Lid (1)

Grow Tray (1)

Lab Base (1)

Starter Plugs (66)

Octa-Bubbler Pump and Cord (1)

Electric Fan (1)

Black Cord (1)

Sun Grip Light Hanger (1)

Great White Premium Mycorrihaze (1)

Grow block clips (5)

Flora Flex Cap (5)

Multipurpose Ties (19)

Yard Stick (1)

Colored Sharpies (4)

1 tbsp (1)

1/4 tsp (1)

1-liter measuring cup (1)

Pitcher (1)

Light (1)

Light Cord (1)

Gray PVC Pipe (4)

White PVC Pipe (9)

Elbow Connector PVC (8)

Clear PVC Pipe 3 Holes drilled and sanded + sealed caps (2)

Also, Josie asked me to write a paper for the WISRD Journal, so I will be working on that this summer. Right now I’m looking over the publication archives to get an idea of what an article should look like.

-Dani B.

May 18, 2018

Updated by: Dani B.

Today we are starting to wrap up our work in WISRD for the year, so we uploaded scanned versions of all out documents (hard copy) from the Hydroponics lab.

The file path on the WISRD computers is Network > dumbledore > assets > Life Sciences > Hydroponics

Here’s our plan for the last three days in WISRD this year:

Friday: Print caps, transfer documents on to server

Monday: Sand and attach caps, seal caps

Tuesday: Design and print stabilizers

May 15, 2018

Updated by: Dani B.

Today we went downstairs to the lab to look at the pumps, lighting system, and structure. We also sketched out where we wanted to position the lab underneath the stairs taking into consideration the pumps and where we will need elbow connector pipes. 

We decided that we would use the reservoir for clean water on the ground level, but not above the tubes because the stairs don’t have a lip that we can drill through. We also strategized about how to support the PVC pipes because we don’t have any way to hang them (the extension we were planning to use are part of the fire system and we can’t attach anything to them). Here’s our sketch and we will make a plan soon. (The drawing is meant to be vertical, not horizontal, but I couldn’t rotate it because of the web browser I’m writing this on.)

We’ll have to wait until we can print these because the 3D printer is being fixed at the moment.

-Dani B.

May 14, 2018

Updated by:  Dani B.

Since my last journal, we made a lot of progress with our PVC pipes. We worked with the 3D printing team and got two 3D printed caps for our first pipe, with the measurements listed in the journal below. Once the caps were on, we put sealant around the edges. This much we were able to present at the Spring poster session, which went really well. We got a lot of great questions on our project and people seemed to be impressed! We tested the caps with water and they work well. We also spent some time in the lab downstairs trying the figure out how we could position the pipes. We may end up hanging the pipes on a cord with a carabiner so that the grade can be adjusted. Since the frame is slightly shorter than the pipes, we are planning to 3D print a U-shaped stabilizer so that the tubes don’t slip out of the frame. We sketch up designs for those soon and put them in the journal. Next, we will start working on the sensors for the lab.

Today, we drilled the holes in the tubes. There are three per tube, so six in total. They’re each one inch in diameter and evenly spaced. We are going to put mesh netting inside of each of the holes so that we can keep the baby plants inside. This way, the mesh will be tight enough to hold in the plant so that it’s not swept away by the current of the water, but loose enough so that the roots can grow through the mesh when the plant gets older.

We did have one small issue with the drilling. Because the plastic is so hard, it is not easy to drill and can crack. We accidentally drilled too quickly into one of the holes and got a small crack on the top of the pipe. It shouldn’t be a big problem because there probably won’t be water in that area and we can put sealant on the crack. Once we had drilled, Sadie sanded down the holes and got the plastic out of the tube, and Ximena created the drill centers and drilled into the new pipe.

-Dani B.

April 24, 2018

Updated by: Dani B.

Yesterday we worked on the caps for the PVC tube that our plants will grow out of in the lab. We decided to make one side higher, so less water flows in, and the other side lower, so that more water flows out and into the used water reservoir. Here’s some sketches of how we want it to look: (I wasn’t able to rotate the image)

We decided to have the PVC pipe on a slant, with the fresh water reservoir above it, underneath one of the steps, and the used water reservoir underneath it, on the ground or in the tray. This will help to prevent molding because the water will be flowing through constantly, but we can manage the amounts.

We’ve started talking to the CAD team about having the caps 3D printed, so needed to try it out cheaply and quickly. We decided to use masking tape in the dimensions of the caps, which will be 2.737 inches on the higher side and 1.5 inches on the lower side. Here’s the water flowing through the PVC pipe, using the masking tape caps:

In the photo, you can see that the tape “cap” on the other end of the tube is higher, while the cap end in the foreground is lower, so only the necessary water stays in the tube, and the rest flows over the top of the cap, preventing molding and keeping the water in the tube at a constant salinity at all times.

Last Friday, I researched how the AC (alternating current) power supply works and how we will use it to measure the charge of our solutions. Here’s the notes I took:


Objective: Measure the charge of the salinity solutions (unit of measure of amps), using an AC (alternating current power supply)

Why AC Power Supply?: With the DC (direct current) power supply, the positive probes were clogged with negative chlorine ions and the negative probes were clogged with positive sodium ions. Because the negative and positive probes were direct current, they were continuously attracted the same opposite charge ions over an extended period, causing the probes to become blocked. By using the AC power supply, there won’t be time for the probes to become clogged because the probes will constantly alternate between negative and positive charges.

AC Power Supply: Current flows one way from a source, reverses, flows the other way. Occurs multiple times per second at a rate determined by the frequency which is typically 50 or 60 hertz.

AC Power Measurements- Current:

  • AC power supply measurements are equivalent to DC
  • NOT average readings, AC current readings are Root Mean Square (RMS)
  • Power can be measured by observing waveform, breaking up into tiny time slices. For each moment, determine power dissipation using (P=12xR)
    • R = resistance
  • R is constant, since it’s internal resistance, can be removed from final equation
  • Equation for effective power = Ieff = √(I12 + I22 + …. + In2 ) / n
    • n = number of time slices in waveform
  • Figure 1: Visual representation of waveform/time slices
      • Image: Amtek Programmable Power
  • Effective equivalent of DC calculation
  • To find the RMS current value, transfer value from a sum to an integration

Integrations and Derivatives:

  • To find a function’s derivative, use the slope formula: ∆X / ∆Y = slope
  • Translates to: Δy / Δx =  f(x+Δx) − f(x) / Δx
  • Simplify, and then push ∆x as close to zero as possible
  • Example for function f(x) = x^2
  • Or, the slope at x is 2x
  • The integral of a function is the opposite of the derivative: if the derivative of f(x) = x^2 is 2x, then the integral is x^2
  • The integral symbol is ∫, the “s” signifying the summing of slices

What are ions?

  • Look at periodic table to determine the amount of protons and electrons it takes to balance the element.
  • For an atom to be stable they must have eight electrons.
  • Through chemical reactions atoms gain and lose their electrons to make sure they have eight electrons.
  • Those elements who have eight electrons or multiples of eight, are not susceptible to chemical reactions.
  • Elements who have eight electrons in a single ring as well as two or three electrons are highly unstable and are able to react with other elements.  
  • See glossary of power supply terminology here: https://www.cui.com/catalog/resource/power-supply-glossary.pdf

AC Power Supply Background

In a switch mode power supply (SMPS), the AC mains input is directly rectified and then filtered to obtain a DC voltage. The resulting DC voltage is then switched on and off at a high frequency by electronic switching circuitry, thus producing an AC current that will pass through a high frequency transformer or inductor. Switched-mode power supplies are usually regulated, and to keep the output voltage constant the power supply employs a feedback controller that monitors current drawn by the load.

-Dani B.

April 13, 2018

Updated by: Dani B.

Today we finished our poster for the WISRD Poster Presentation and Lecture on April 30. Yesterday, we were downstairs in  the lab space, working on our lab model. We could see that in order to minimize unnecessary energy use, it would be best to use a water-flow model instead of using a pump. That means we would have the clean water resevoir at the top of the lab, most likely mounted to the underside of the stairs. Then the water would flow into the tube and through a hole in the bottom cap to change the concentration. I’ll attach a picture of our sketches next week.

-Dani B.

March 20, 2018

Updated by: Dani B.

Today Sadie and Ximena went downstairs to get an estimate of how the new lab will fit in the space we have under the stairs. They looked at the drafts, and are starting on a Sketchup of the lab. I (Dani) worked on the poster for the Spring Poster Presentation today. We’re using the same format, but rewriting the background and current research, as well as connecting each of the things we have worked on or run into in our research proccess to content that can be extrapolated from the context. We are also still working on compiling a list of all our materials for the lab, but we’re getting ready to cut our PVC pipe!

-Dani B.

March 16, 2018

Updated by: Dani B.

We’re now using the DC Power supply to collect data on the amp of each molar solution, which is represented by dq/dt.

Yesterday, we had a negative and positive probe and the probes ended up corroding. There were sodium ions and chlorine ions, and the chlorine went to positive and sodium to negative probes, so the probes got clogged and corroded. In order to finish getting the amps, we have to figure out what is clogging up the probes and how to counteract this. Here’s a drawing of the circuit with the DC power supply:

Seven fundamental laws of physics: Length, mass, charge, time, stuff, temperature, luminosity

Everything can be described in seven fundamental concepts. Time is used as seconds but can also be the time takes light to travel or in similar more specific contexts, temperature is in kelvin scale (with absolute zero as zero) mass is kg, g, etc., stuff (given the unit of a mole- which is 6.02 x 10 to the 23), luminosity is lumen; candles. Amps is not fundamental, so it must be a relationships between of the fundamentals, charge to time. Represented as dq/dt, delta charge over delta time.

So later in the class we figured out that in order to get rid of the sodium clogging up the negative probes, then we can switch the positive and negative probes. Then, the sodium would just go to the other side, and we would have to keep switching. This is the purpose fulfilled by the AC, alternating current, power supply, which Joe has ordered for us. Our plan is to start with the AC power supply doing a few zero mole solutions and then making sure that we have a straight line. After that we could start running all the rest of our solutions through and see if we have a linear relationship.

-Dani B.

February 27, 2018

Updated by: Dani B.

Today we finally finished our calibration curve using copper 2 sulfate. We used the 0.20, 0.14, 0.08 mol solutions. We used the PASCO Spectrometer to identify and create a calibration curve. Our calibration curve looked great! Our absorbance rate had a steady increase as we increased the concentration of copper 2 sulfate. Next, I made an unknown concentration of copper 2 sulfate in the lab, I knew it had a concentration 0.17, but Ximena did not. She placed the cuvette of this ‘unknown’ solution into the Spectrometer and turned it on. The spectrometer gave her an absorption reading of 0.41 (shown at the bottom left hand corner.) Using the calibration curve, which is the strait horizontal line running through the graph, Ximena was able to approximate the exact concentration of the ‘unknown’ solution. She guessed 0.168 mols. The software that we used gave Ximena a green dot where she approximated the consecration because she had a very good approximation. The software would have given her an orange square if she was any further away.

With all this discovered, Ximena and I are hoping to make a calibration curve like the one below using NaCl instead of copper 2 sulfate. If we have a calibration curve like this using NaCl, we could determine the concentration of our water used in the hydroponics lab!

February 13, 2018

Updated by: Dani B.

Today Sadie and Ximena put the spectrometer graphs on the server, so they will be adding them to this page when they journal today. Dani worked on creating a preliminary list of the materials we will need to build a new lab. Some, or many, of them we could repurpose from the old lab, so we will be taking inventory of what we have already and seeing how we can reuse parts. From there, we’ll finalize what we need to purchase and get everything gathered so we can begin building. The list is attached below and will be updated as we get a better sense of what we’ll need along with lab extensions like resevoir tank valves and lighting system materials.

Item: Clear piping

Dimensions: 39 in L, 3 in Diameter

Quantity: 4

Item: Plastic tray

Dimensions: 39 in L, 38 in W, 3 in Depth

Quantity: 1

Item: Resevoir tank

Dimensions: 9.5 in L, 19.5 in W, 20 in Depth

Quantity: 8

Item: Structural tubing

Dimensions: 38 in L

Quantity: 4

Item: Structural tubing

Dimensions: 28 in L

Quantity: 4

Item: Structural tubing

Dimensions: 39 in L

Quantity: 4

Item: 90 degree tubing connectors

Dimensions: TBD, circumference uniform with structural tubing circumference

Quantity: 8

-Dani B.

February 7, 2018

Updated by: Dani B.

Yesterday we ran all the solutions through the spectrometer. We’re creating a calibration curve for each solution of the absorption levels of each. Last time we ran into an issue because when running the solutions through the spectrometer, we were supposed the go from least to greatest molarity, but accidentally we went out of order of molarity, which altered the curve. To run the spectrometer, we’re using Behr’s Law, so there are going to be two axes, Absorption and Concentration. According to Behr’s law, we should have a linear graph because the absorption increases as the concentration increases. However, we’re getting a very different graph that isn’t anywhere near linear.Since the graph on this test wasn’t what we were expecting, we thought that the problem may be re-occurring and decided to take new samples of the each molarity solution and re-run all the tests. Hydroponics team member Sadie G. will have the graphs for today’s tests by the end of this class period, so we will update the page and add those images when we have run the tests again. Once we’ve gotten a linear graph, we will identify a slope. Until then, we are going to document each trial and will probably get in touch with Pasco via email to rule out whether the issue is with our use of the spectrometer.

-Dani B.

December 11, 2017

Updated by: Dani B.

Set up Hydroponics page, added dropdowns
Set goal, created step-by-step plan
Set timeframe to complete each step

-Dani B.