Experiment

    The actual experiment encompassed a 14 day growth period. For the previous three weeks, I cultivated 2 specimens of Helianthus annuus in organic soil to provide a starting point for the seedlings. 

    The sunflowers were transplanted into a hydroponic system. Its consists of 2 inner pots, which are filled with the inert growth media coco coir, shredded coconut husk. The material is stabile and gives necessary oxygen to roots and a correct water-to-air ratio. The inner pots were covered with cheesecloth, placed within a outer tray and enclosed in a trash bag. The bag was tightened around the sunflower stems. The tray contained the nutrient solution, which was absorbed to the inner pots and sunflowers. The bag also acted as a barrier, preventing any materials from leaving or entering the system. At the beginning of the growth period, I washed the soil off the sunflower roots, placed them in the coco coir, added nutrient water, and closed the systems.
   
    The first specimen was labeled sunflower A; the second, sunflower B. Nutrients were measured using a CF (Conductivity Factor) meter, which measures conductivity of the liquid and thus the total dissolved ions (nutrients).

    During the first week, the systems were given the same nutrient solution. Consisting of 2 liters with a 0.78% liquid fertilizer dilution and 0.39% magnesium sulfate concentration, it provided the base nutrients for the sunflowers (please see Data). Registering a 19 in CF, the first week was used to transition the specimens to a hydroponic environment, and to actively collect data on the normal intake of nutrients. This change was viewed using a CF reading everyday. To ensure proper data, water lost through transpiration was replaced BEFORE the sample was taken. The average temperature was also noted.

    Starting the second week, Sunflower A was replenished with more nutrient solution back to the 2 liter original amount at the 19 CF default. It  functioned as a control group, with no change. Sunflower B was placed in a system with one liter of 0.05% sodium perchlorate in pure water solution, with a CF of 8. The other nutrient solution was sprayed on B daily to give nutrients.  Special consideration was taken to prevent the perchlorate from contaminating the environment. This system was also be measured for CF.

    At the end of the two week period, both systems were analyzed. Nutrient solutions were measured, and the sunflower's themselves were analyzed through their stems, leaves, and (possibly) flowers. Sunflower A provided comparison and a control to find correlations in sunflower B.

Additional Content and Pictures:
    Materials:
Hydroponic system
    2 containers w/lid
    2 pots
    2 sunflowers
    cheesecloth
  coco coir
water (filtered)
liquid fertilizer
epsom salt
nutrient meter
CF meter
0.05% solution of sodium perchlorate NaClO4

control group: sunflower A
experimental group: sunflower B
independent variable: perchlorate in water
dependent variable: growth and function of sunflower
Looking for: Correlation between growth of specimen B and levels of sodium perchlorate in water

    Safety considerations: All equipment that was in contact with the perchlorate solution was sealed in a disposal bag, and leftover solution was filtered into a container awaiting disposal. I made sure to prevent spillage of solution or release into the ecosystem.

Dried Coco Coir and Liquid Nutrients               


Nutrient Meter and Magnesium Sulfate (Epsom Salt)

                          
             
Hydroponic System with Bag, Sunflower, and Inner Pot (Week 1)

Two Hydroponic Systems with outer covers removed (Week 2)