Fertilizers Lab Report

Purpose: The reason we conducted this experiment is to find out if adding nitrates and phosphates to the ground like with fertilizers would grow more algae and deplete the water of oxygen. My hypothesis is that the nitrate and phosphate mix would grow more algae. (Writers Note: not reading the article on the subject.) The reason I thought this was that the nitrates and phosphates would slow down the growth if they were added to the water by them selves. So I thought that maybe if they were added together they would cancel each other out being a natural part of the environment to some degree.
Procedure: The first thing that we did was to take a water sample from a lake or natural water source. After that we split into the eight test tubes. We measured the amount of green light with a spectrometer in the first test tube and recorded the data. After that we added the daily drops. Every day we repeated the process except for the spectrometer in which we used it on the last day of testing.
Analysis: It appears as if the as if the phosphate solution has grown more algae according to the spectrometer but according to the eye it appears that it has changed the least. This might have occurred because of the amount of alga particles floating during the testing causing it to read higher. This contradicts my hypothesis because the phosphate nitrate solution had the least amount.
Conclusion: My hypothesis was not supported by the data results. The new question I have is why algae would grow more if nitrates and phosphates were separated but together the alga does not grow well at all. One way of finding this out is by researching the chemical that the alga forms when it ingests the nitrates and phosphates. Maybe the chemical when the nitrate and phosphate mix is ingested it forms a poisonous chemical that pollutes the water and kills the algae.