Does the addition of dark chocolate to clay pebbles in a growing bed increase the energy output by the spinach?
Note: Oxygen can be used to measure photosynthetic productivity, soby Hypothesis-
Dark cocoa powder, like coffee, contains high nitric oxide. If is mixed with the clay rock, then fish tank will exceed the normal/ initial oxygen level of the fish tank without killing the spinach as the nitric oxide will react with oxygen in the clay pebbles. The reaction would result in nitrite and then follow the nitrogen cycle.
Variables-
Independent: The dark cocoa because 3 out of 4 of the growing beds will have clay rocks mixed with dark cocoa powder.
Dependent: The oxygen levels found within the tank, plant growth, and ammonia production.
Controlled: Growing bed with only clay rocks as the growing medium, the fish(including its food), the fish tank and its environment.
Materials-
6 Hershey Cocoa, Specially Dark 8 oz
8 Basil or Great basil seeds
4-5 Viastone Expanded Clay Rocks 50 liters
Marineland Bio-Wheel Penguin Power Filter
16 Fry Oreochromis aureus, commonly known as Blue Tilapia (baby)
4 aquariums (5 gallons) 16.2 in L x 8.4 in W x10.9 in H
Aqueon Begonia Aquarium Plant (optional)
Pure Water gravel, 5 lb bag
4 Aquaponics or Hydroponics Fail Safe Auto Bell Siphon Kit For Small Shallow Grow Beds 3"
A clean bucket
4 Water pump with inline pump
4 wooden box 15 in L x 7 in W x 3 in H with four 12 inch legs (Growing bed)
Method/Protocol (Preparation)-
Assuming the fish tank comes pre- made, fill the bottom of the tank with pure water gravel until it reaches a one inch level.
Add an aquatic plant (optional)
Fill your tank approximately one-third full with room temperature (73 F) water from a clean bucket.
Place a water pump at the bottom of the fish tank and attach its inline pump.
Switch the pump on.
Place the baby tilapia inside the fish tank.
Have an adult drill a hole large on the center of the wooden box. Make sure that the hole is large enough to insert the bell siphon.
Insert the bell siphon into the hole and insert the tube attached to the bell siphon into the water. Repeat for each growing bed.
Fill each growing bed one-third of the way with the clay rocks.
Label each growing bed, so that the beds can be easily identified
Mix 3 of the 4 growing with dark cocoa powder; one with 2.5 oz of powder, the second with 5 oz, and the third with 10 oz. (Note: Remix every 3 weeks and add the correct amount in each container)
Then use your thumb to create a space to insert the basil seed. Insert the seed in to the hole and cover it back up. Repeat this twice for each growing bed.
Method/ Protocol (Experiment)
Every morning measure oxygen levels by inserting the fresh water strips into the fish tank for one minute.
Wait one to two minutes for the strip to change color.
Then use the reference page or key provided in the box to determine the dissolve oxygen concentration.
Use a thermometer to make sure that the temperature is no lower than 60 F and no higher than 80 F.
Place a lamp a foot above the growing bed and turn on during the morning at the same time.
Repeat steps for each tank every morning for 44 days.
How will data be collected? When?
I will collect data by using the dissolved oxygen test strips from the EasyStrips 6 in 1 and inserting it into the water of the fish tank for 60 seconds. I will repeat this every morning at 7:45 (before school starts). I chose the morning so I can place a light over the during daylight (school hours) and off after school (night time) in an attempt to model an outside environment. This would allow for photosynthesis to occur at a normal rate.
Note: I will use two test strips in two different location to ensure my data is accurate. How will data be reported?
The data will be reported in two way, a line graph and bar graph. For every plant, I will use line graph to show fluctuation in oxygen levels progress, because the plants is continuously producing oxygen. The second method would be a bar graph in which the mean oxygen levels for each fish tank would be compared. This will allow us to conclude which amount of dark cocoa powder
How will data be analyzed?
If the plant does not die from high nitrate concentration and the average mean of dissolved oxygen levels is greater than the levels of the control, then one could conclude that dark cocoa powder act as a catalyst for photosynthesis by aiding in the increase in oxygen levels.
If the plant does not die from high nitrate concentration and the average mean of dissolved oxygen levels is less than the levels of the control, then one could conclude that dark cocoa powder may have hindered or had no significant effect on photosynthetic production.
If the oxygen levels are negative or the plant dies and oxygen from high nitrate levels, one can assume that the nitric oxide (NO) from the dark cocoa powder (reacts with oxygen produced by photosynthesis)forms nitrite (2 NO2-), which is converted be the plant to nitrate (NO3-). However, the nitrate produced from the dark cocoa plant would be additional nitrate to plant and may not be absorbed resulting a runoff back to the fish tank and fish death due to an excess of nitrate.