Hydroponic Plants

By: Aakash Talathi and Brett Henry


In our overpopulated world, there has become a great demand for food in recent decades. More and more land is being used for the real estate and business industries while the agricultural industry is losing space. To solve this problem more than one solution will have to be presented. One of these solutions is for farmers to grow certain small plants in water. Hydroponics is the process of growing plants in liquid or sand. During this process it is beneficial to the plants if some extra nutrients are added. It is known that certain plants such as flowers can be grown in water. It is also known that some small vegetable plants can grow in water. But in which substance would the plants grow best in? Plants require some essential vitamins and minerals to live, but which easily accessible nutrients are most beneficial to seeds when they germinate?


The purpose of this experiment is to conclude which mineral, salt or sugar, is most beneficial to the plant during germination. The question that will be answered in this experiment is; In which solution of essential nutrients for plants do the most plants germinate?


If salt and sugar are added to the solutions in which the plants grow, then more of the plants that grow in the salt solutions will germinate because salt is essential for the plant’s growth.


Traditionally plants anchor their roots into the ground for two reasons, the soil will keep them stable against natural factors such as strong winds or heavy rains and also they will be able to soak up water from deep in the soil. In hydroponics the do not have this option due to the lack of soil for the roots to latch on. Instead, the roots are in a free float in the nutrient solution because factors such as weather and lack of water do not affect these plants in hydroponics. According to recent studies there is no one solution that best affects the plants growth as long as the solution has salt it in. This may be due to the iodine in the salt that causes a growth in the plant. There are some issues regarding hydroponics that are a factor in real life as well as our experiment. One such major issue would be the lack of nutrients that plants receive right after they germinate. Essential nutrients such as calcium, magnesium, sulfur, copper, iron, and zinc are often missing in this process which could harm the plant later in its life. If the plant is lacking these minerals then the crop it may bear would also be lacking nutrients and may lead to deficiency problems with the organism that eats them. On the contrary, studies show, that if hydroponics is executed right then the plant will be healthier than it would have been growing in soil. In soil the plant has to extend its roots and search for the nutrients. Whereas a plant growing in a solution will have the same amount of nutrients all throughout its growing space because solutions equal mix all the solute into the solution.

Parts of The Expirement

  • Dependent variable - Number of plants germinated

  • Independent variable - Type of nutrient added to the solution

  • Control - Seeds grown in tap water without any added nutrient

  • Experimental group - Seeds grown in either sugar or salt water

  • Factors held constant - Amount of sunlight, Amount of solution, Amount of nutrient added to solution


  • 150 Lentil Seeds

  • 150 Plastic cups

  • Salt, .3 oz. (.007 oz. per cup)

  • Sugar, .3 oz. (.007 oz. per cup)

  • Water, 150 fl oz. (1 oz. per cup)

  • Ruler and Sharpie

  • Flat Indoor Surface with Sunlight


  1. Mix .4 oz. of salt into .4 Gallons of water.

  2. Evenly distribute the water into 50 plastic cups, each cup will have one oz. of liquid in it.

  3. Label the cups “salt” to ensure they don’t get mixed with other variables.

  4. Mix .4 oz. of sugar into .4 Gallons of water.

  5. Evenly distribute the water into 50 plastic cups, each cup will have one oz. of liquid in it.

  6. Label the cups “sugar” to ensure they don’t get mixed with other variables.

  7. Fill the remaining cups with 1 oz. of water.
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The most important calculation that could be done here would be the percentage of the plants on a certain day. On day 9, 100% of the plants were grown in Sugar Water. On day 12, 49 plants had germinated and 30.61% were grown in tap water. 48.97% of the plants were made up by sugar water and 20.4% were made up of salt water. On the 15th day, 66 plants had germinated. 31.81% being in Tap water, 45.45 in Sugar Water and 22.72% being in Saltwater. From these percentages one can see that though plants grew in sugar water the best, not one plant type dominated the percentages on any day. Another important aspect to look at is the rate of increase from the 12th day to the 15th day. The number of plants grown in sugar water is 24 on the 12th day and 30 on the 15th day. The increase percentage is about 25% within these days. The number of plants grown in Tap Water is 15 on the 12th day and 21 on the 15th day. This number also increased by 6 plants, but unlike the sugar the tap water increase rate rose 40%.

The last category, saltwater had the biggest increase out of all the categories. The saltwater plants went from 10 on the 12th day to 15 on the 15th day. This was a 50% increase. This information shows us that plants grown in Salt and Tap water are more prone to growing after 10 days, rather than before it, like sugar.

Statistical Analysis

To determine if the salt or sugar had a significant impact on the plants in this experiment a T-Test was done on the two Independent variables to see if either of the two had an significant impact on the plant. Though we had inferred that salt did have a significant effect on the plant, the T-Test proved otherwise. In a T-Test if a P value is less than 0.05 it is regarded as statistically significant. The P-Value for Salt was 0.09 which is statistically very high, here we realized that the salt did not have a great effect on the plants at all, this is supported by the fact that even the tap water acted as a better habitat for these seeds. The P-Value for Sugar was 0.03 which is considered statistically significant and because of this we can support the claim that sugar water helps seeds germinate.
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Sugar has the greater positive effect than salt for the growth of seeds grown hydroponically.

This is directly supported by the data recorded which states that seeds placed in sugar water grew faster and in greater quantity. Though we did see seeds that were grown in both sugar and salt water germinate, the seeds grown in salt water did not germinate in as great of numbers as compared to the seeds grown in sugar water. Because plants do not germinate instantaneously the first 6 days were a growing period for the seeds. None of the seeds germinated during this time period though many developed roots. After 9 days, the only seeds that were grown and germinated were seeds from the sugar category. This led us to believe that plants grown in sugar water were going to be the plants with the most germinations which went against our hypothesis. After 12 days the most plants germinated were still the ones grown in the sugar water, though at this point some plants from the other groups had germinated completely. On the 15th day, the last day that the number of plants that had germinated were counted, it seemed as though that all the plants that were going to germinate had germinated. The 15th day is important because it shows our final data. 15 plants grown in salt water had germinated, 20 plants grown in tap water had germinated and 30 plants grown in sugar water had germinated. The increase rate was also important to our data. It showed us that the plants in the sugar water were almost twice as likely to germinate faster than plants grown in tap or salt water.

Plants that grow in water need some form of nutrients as they are unable to obtain any in an enclosed environment. Plants make sugar by themselves yet when they have access to an abundant amount of sugar they grow better then when they have access to an abundant amount of salt or access to no nutrients. The data shows that sugar is more important to plants during germination than salt. The plants that were grown in tap or saltwater had a lower success rate of growing than those that grew in sugar water. Though it seems as though on the final measure tap water and sugar water had relatively close numbers regarding how many plants germinated the reason that we expressed the sugar being the best option is because the plants that grew in sugar water were much healthier as opposed to the plants that were growing in tap water which, as a whole, were much less healthy. From this we can reason that sugar water is a better solution to use to grow plants hydroponically, because the plants that grow in this solution grow faster, healthier and are greater in quantity than salt and tap water.


The purpose of the experiment is to investigate the effect of different minerals on the growth of plants hydroponically by comparing the number of seeds germinated when subjected to either saltwater or sugar water over a 15 day period with a control of tap water. A significantly greater number of seeds had germinated when grown in sugar water over salt and tap. As the graphs show, the plants grown in sugar water germinated earlier, faster and were in greater quantities. At the end of the experiment the sugar water plants had 30 plants germinated, the tap water plants had 21 and the salt water had 15. The hypothesis that if salt and sugar are added to the solutions in which the plants grow, then more of the plants that grow in the salt solutions will germinate because salt is essential for the plant’s growth was not supported. This experiment only relied on data that was taken every three days and could be improved if data was taken more frequently such as daily or twice a day. Additional investigations using different and more various minerals would be a great experiment. Also, investigating different concentrations of the mineral in the solutions to determine which concentration is the best for the plant’s growth would prove to be a great experiment.

Possible Errors

It is possible that there could have been inaccuracies in this experiment that could have been caused by mishaps in mixing the nutrients in the solutions or in measuring amounts of liquid. At the beginning of the process we could have been slightly off with the measurement of nutrient added to the water and the amount of water put in each cup. Also the cups for the growth of the plants were too small and caused a large problem for the experiment so the previous cups were switched with new, larger cups.


The information received from this experiment can be used to improve the efficiency of and optimize growth in plants through hydroponics. The data will show which nutrient will help the plants grow best when grown through the process of hydroponics. This can help with the growth of crops in areas where there is a small amount of farmland such as in urban areas. This can also apply to the transportation of plants that needed to be kept alive in the process. Because the population in the world is rising it is important that we find more efficient ways to grow food so that we can feed the world.

How to Better This Expirement

This experiment could be improved to involve more nutrients to be tested which widens the search for the best nutrient. Also the experiment could be altered to have a longer period of time to see if plants that did not show promise at the beginning could have greater advantages later. Another way this experiment could be changed and improved is by changing the amount of nutrient in the solution in order to find the best ratio of water to nutrient.


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Stevens, James M. "Grow Your Own Vegetables Without Soil1." EDIS New Publications RSS. N.p., n.d. Web. 30 Sept. 2014.

"What Is Hydroponics?" Simply Hydroponics. N.p., n.d. Web. 27 Sept. 2014.

McCall, Wade W., and Yukio Nakagawa. "Growing Plants without Soil." N.p., n.d. Web

Klefstad, Karen. "The Effects of Sugar & Salt Water on Plants." LIVESTRONG.COM. LIVESTRONG.COM, 12 Dec. 2010. Web. 29 Sept. 2014.